Circulating palmitoyl sphingomyelin levels predict the 10-year increased risk of cardiovascular disease death in Chinese adults: findings from the Da Qing Diabetes Study.

BACKGROUND: Higher levels of palmitoyl sphingomyelin (PSM, synonymous with sphingomyelin 16:0) are associated with an increased risk of cardiovascular disease (CVD) in people with diabetes. Whether circulating PSM levels can practically predict the long-term risk of CVD and all-cause death remains unclear. This study aimed to investigate whether circulating PSM is a real predictor of CVD death in Chinese adults with or without diabetes. METHODS: A total of 286 and 219 individuals with and without diabetes, respectively, from the original Da Qing Diabetes Study were enrolled. Blood samples collected in 2009 were used as a baseline to assess circulating PSM levels. The outcomes of CVD and all-cause death were followed up from 2009 to 2020, and 178 participants died, including 87 deaths due to CVD. Cox proportional hazards regression was used to estimate HRs and their 95% CIs for the outcomes. RESULTS: Fractional polynomial regression analysis showed a linear association between baseline circulating PSM concentration (log-2 transformed) and the risk of all-cause and CVD death (p < 0.001), but not non-CVD death (p > 0.05), in all participants after adjustment for confounders. When the participants were stratified by PSM-tertile, the highest tertile, regardless of diabetes, had a higher incidence of CVD death (41.5 vs. 14.7 and 22.2 vs. 2.9 per 1000 person-years in patients with and without diabetes, respectively, all log-rank p < 0.01). Individuals with diabetes in the highest tertile group had a higher risk of CVD death than those in the lowest tertile (HR = 2.73; 95%CI, 1.20-6.22). CONCLUSIONS: Elevated PSM levels are significantly associated with a higher 10-year risk of CVD death, but not non-CVD death, in Chinese adults with diabetes. These findings suggest that PSM is a potentially useful long-term predictor of CVD death in individuals with diabetes.

Evaluation of a First PET Tracer Suitable for Imaging the Sigma-2 Receptor in the Brain of Nonhuman Primates.

The sigma-2 receptor (σ2R), recently identified as transmembrane protein 97, is expressed in many cell types and mediates important functions in both the peripheral and central nervous systems. Over the years, σ2R has emerged as a potential therapeutic target for cancer and neurological disorders such as Alzheimer's disease (AD). The currently available σ2R radiotracers have been developed primarily for cancer imaging with limited brain uptake. Here, we report the evaluation of the first brain penetrant 18F-labeled radiotracer suitable for positron emission tomography (PET) imaging of σ2R in nonhuman primate brain.

18F-Labeled o­aminopyridyl alkynyl radioligands targeting colony-stimulating factor 1 receptor for neuroinflammation imaging.

We report the design, synthesis and evaluation of five o­aminopyridyl alkynyl derivatives as colony-stimulating factor 1 receptor (CSF-1R) ligands. Compounds 4 and 5 with the fluoroethoxy group at the meta- or para-position of the phenyl ring possessed nanomolar inhibitory potency against CSF-1R with IC50 values of 7.6 nM and 2.3 nM, respectively. Radioligands [18F]4 and [18F]5 were obtained in radiochemical yields of 17.2 ± 5.3% (n = 5, decay-corrected) and 14.0 ± 4.3% (n = 4, decay-corrected), with radiochemical purity of > 99% and molar activity of 9-12 GBq/µmol (n = 5) and 6-8 GBq/µmol (n = 4), respectively. In biodistribution studies, radioligands [18F]4 and [18F]5 showed moderate brain uptake in male ICR mice with 1.52 ± 0.15 and 0.91 ± 0.07% ID/g, respectively, at 15 min. Metabolic stability studies in mouse brain revealed that [18F]4 exhibited high stability while [18F]5 suffered from low stability. Higher accumulation of [18F]4 in the brain of lipopolysaccharide (LPS)-treated mice was observed, and further pretreatment of BLZ945 or CPPC led to remarkable reduction, indicating specific binding of [18F]4 to CSF-1R.

The Sigma Receptors in Alzheimer's Disease: New Potential Targets for Diagnosis and Therapy.

Sigma (σ) receptors are a class of unique proteins with two subtypes: the sigma-1 (σ1) receptor which is situated at the mitochondria-associated endoplasmic reticulum (ER) membrane (MAM), and the sigma-2 (σ2) receptor, located in the ER-resident membrane. Increasing evidence indicates the involvement of both σ1 and σ2 receptors in the pathogenesis of Alzheimer's disease (AD), and thus these receptors represent two potentially effective biomarkers for emerging AD therapies. The availability of optimal radioligands for positron emission tomography (PET) neuroimaging of the σ1 and σ2 receptors in humans will provide tools to monitor AD progression and treatment outcomes. In this review, we first summarize the significance of both receptors in the pathophysiology of AD and highlight AD therapeutic strategies related to the σ1 and σ2 receptors. We then survey the potential PET radioligands, with an emphasis on the requirements of optimal radioligands for imaging the σ1 or σ2 receptors in humans. Finally, we discuss current challenges in the development of PET radioligands for the σ1 or σ2 receptors, and the opportunities for neuroimaging to elucidate the σ1 and σ2 receptors as novel biomarkers for early AD diagnosis, and for monitoring of disease progression and AD drug efficacy.

Characterization of the metabolism of aloin A/B and aloesin in rats using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

Aloin A/B and aloesin are the major bioactive constituents in Aloe vera, with diverse pharmacological activities, including anti-bacterial, anti-tumour, anti-inflammatory and intestinal regulation. However, the in vivo metabolism of aloin A/B and aloesin is still unclear. In this study, the metabolic processes of aloin A/B and aloesin in rats were investigated using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) and MetaboLynx™ software with the mass defect filter technique. Based on the proposed method, the prototype components of three compounds were all detected in rat plasma, urine and feces. Meanwhile, 25 aloin A/B metabolites (six phase I, three phase II, 16 phase I combined with phase II) and three aloesin metabolites (two phase I and one phase II) were detected in rats after oral administration of aloin A, aloin B and aloesin, and the main biotransformation reactions were hydroxylation, oxidation, methylation, acetylation and glucuronidation. In addition, aloin A and aloin B can be transformed into each other in vivo and the metabolic profiles of aloin A and aloin B are identical. These results provide essential data for further pharmaceutical research and clinical application of aloin A/B and aloesin.

New caffeoyl derivatives from Elephantopus scaber.

Three new caffeoyl derivatives (1-3), together with two known ones (4-5), were isolated from the whole plant of Elephantopus scaber Linn. The structures of the new compounds were elucidated using detailed spectroscopic analysis. Compound 4 was obtained and its NMR data were given for the first time. All isolates were evaluated for their anti-inflammatory activity against lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production and pro-inflammatory cytokines release in RAW 264.7 cells. Compounds 2-5 showed mild inhibitory activities with IC50 values ranging from 64.78 to 87.21 µM, and 3-4 could inhibit LPS-induced tumor necrosis factor-α (TNF-α) production.

Antidepressant-like effect and phytochemical profile of supercritical CO2 extract from Citri reticulatae pericarpium.

Citri reticulatae pericarpium is a condiment, adding much flavor in Chinese food. Also it can be used to treat depression as a Traditional Chinese Medicine (TCM). The study here aimed to evaluate the antidepressant effect between the supercritical CO2 extract (SC-E) from Citri reticulatae pericarpium and the essential oil extracted by steam distillation (SD-E). And chemical compositions of SC-E were qualitatively analyzed by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) and gas chromatography-mass spectrometry (GC-MS). Compared with SD-E, SC-E showed a stronger antidepressant-like effect in FST and TST mice. And it also decreased the content of monoamine oxidase (MAO) in the cerebral cortex of stressed mice. A total of 60 compounds were identified in SC-E. Among them, 28 compounds were characterized in UPLC-Q-TOF/MS analysis and all are polymethoxyflavones (PMFs). Three main compounds, 3,5,6,7,8,3',4'-heptamethoxyflavone, nobiletin and tangeretin, together account for 66.09% of the total relative peak area. 33 terpenes were identified by GC-MS analysis, such as D-limonene (12.34%), ß-elemene (8.86%), germacrene D (5.59%) and (Z, E)-α-farnesene (5.44%). Polymethoflavones and terpenes are the main constituents of SC-E responsible for its antidepressant-like effect. The study could stimulate further investigations into the antidepressant effects and mechanism of Citri reticulatae pericarpium.

Synthesis and evaluation of new 1-oxa-8-azaspiro[4.5]decane derivatives as candidate radioligands for sigma-1 receptors.

We report the design, synthesis, and evaluation of a series of 1-oxa-8-azaspiro[4.5]decane and 1,5-dioxa-9-azaspiro[5.5]undecane derivatives as selective σ1 receptor ligands. All seven ligands exhibited nanomolar affinity for σ1 receptors (Ki(σ1) = 0.47 - 12.1 nM) and moderate selectivity over σ2 receptors (Ki(σ2)/ Ki(σ1) = 2 - 44). Compound 8, with the best selectivity among these ligands, was selected for radiolabeling and further evaluation. Radioligand [18F]8 was prepared via nucleophilic 18F-substitution of the corresponding tosylate precursor, with an overall isolated radiochemical yield of 12-35%, a radiochemical purity of greater than 99%, and molar activity of 94 - 121 GBq/µmol. Biodistribution studies of [18F]8 in mice demonstrated high initial brain uptake at 2 min. Pretreatment with SA4503 resulted in significantly reduced brain-to-blood ratio (70% - 75% at 30 min). Ex vivo autoradiography in ICR mice demonstrated high accumulation of the radiotracer in σ1 receptor-rich brain areas. These findings suggest that [18F]8 could be a lead compound for further structural modifications to develop potential brain imaging agents for σ1 receptors.

Comprehensive identification of potential antioxidant components in the aerial parts of Polygonum chinense L. var. hispidum using ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

The aerial parts of Polygonum chinense L. var. hispidum are one of the key herbs in Cantonese herbal tea, which is quite a common local beverage in LingNan area of China. Previous investigation has found that this herb possesses antioxidant activity and the ethyl acetate fraction of its ethanol extract shows the strongest antioxidant activity. However, little is known about its antioxidant chemical constituents. The aim of this research was to investigate the active constituents of this plant by identifying and characterizing the chemical profile in ethyl acetate fraction using ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry, which can provide characteristic ultraviolet absorption, accurate molecular weight, and diagnostic tandem mass spectrometry fragment ions. As a result, 85 compounds were identified including 22 flavonoids, 12 ellagic acids, 34 ellagitannins, 16 phenolic acids, and one phenolic amide. All the phenolic compounds identified in this work, especially ethyl gallate, geraniin, chebulagic acid, and quercitrin with the higher peak areas in the ultra high performance liquid chromatography with mass spectrometry chemical profile of this plant, could be the bioactive principles responsible for the antioxidant activity. These findings in the present study could benefit further studies involving the functions and chemicals of this plant, and provide scientific evidence for usage of Cantonese herbal tea.

Design and Synthesis of Molecular Hybrids of Sophora Alkaloids and Cinnamic Acids as Potential Antitumor Agents.

Twenty-five sophora alkaloids-cinnamic acid hybrids (including matrine-cinnamic acid hybrids, sophoridine-cinnamic acid hybrids, and sophocarpine-cinnamic acid hybrids) were designed, synthesized, and evaluated in vitro against three human tumor cell lines (HeLa, HepG2 and A549) with cisplatin as a positive control. Some matrine-cinnamic acid and sophoridine-cinnamic acid compounds exhibited potent effect against all three cancer cell lines, such as compounds 5b, 5e, 5g, and 6d. The structure-activity relationship study of the synthesized compounds was also performed. Preliminary mechanistic studies indicated that compounds 5e and 6d could induce apoptosis in HepG2 cell line. Further, compounds 5e and 6d altered mitochondrial membrane potential and produced ROS leading to cell apoptosis of HepG2 cells. Overall, our findings suggested that these compounds may provide promising lead compounds for further development as antitumor agents by structural modification.

18 F-Labeled benzylpiperazine derivatives as highly selective ligands for imaging σ1 receptor with positron emission tomography.

We report the design, synthesis, and evaluation of a new series of benzylpiperazine derivatives as selective σ1 receptor ligands. All seven ligands possessed low nanomolar affinity for σ1 receptors (Ki (σ1 ) = 0.31-4.19 nM) and high subtype selectivity (Ki (σ2 )/Ki (σ1 ) = 50-2448). The fluoroethoxy analogues also exhibited high selectivity toward the vesicular acetylcholine transporter (Ki (VAChT)/Ki (σ1 ) = 99-18252). The corresponding radiotracers [18 F]13, [18 F]14, and [18 F]16 with high selectivity (Ki (σ2 )/Ki (σ1 ) > 100, Ki (VAChT)/Ki (σ1 ) > 1000) were prepared in 42% to 55% radiochemical yields (corrected for decay), greater than 99% radiochemical purity (RCP), and molar activity of about 120 GBq/µmol at the end of synthesis (EOS). All three radiotracers showed high initial brain uptake in mouse (8.37-11.48% ID/g at 2 min), which was not affected by pretreatment with cyclosporine A, suggesting that they are not substrates for permeability-glycoprotein (P-gp). Pretreatment with SA4503 or haloperidol resulted in significantly reduced brain uptake (35%-62% decrease at 30 min). In particular, [18 F]16 displayed high brain-to-blood ratios and high in vivo metabolic stability. Although it may not be an optimal neuroimaging agent because of its slow kinetics in the mouse brain, [18 F]16 can serve as a lead compound for further structural modifications to explore new potential radiotracers for σ1 receptors.

Design and Synthesis of Matrine Derivatives as Novel Anti-Pulmonary Fibrotic Agents via Repression of the TGFß/Smad Pathway.

A total of 18 matrine derivatives were designed, synthesized, and evaluated for their inhibitory effect against TGF-ß1-induced total collagen accumulation in human fetal lung fibroblast MRC-5 cell lines. Among them, compound 3f displayed the most potent anti-fibrotic activity (IC50 = 3.3 ± 0.3 µM) which was 266-fold more potent than matrine. 3f significantly inhibited the fibroblast-to-myofibroblast transition and extracellular matrix production of MRC-5 cells. The TGF-ß/small mothers against decapentaplegic homologs (Smad) signaling was also inhibited by 3f, as evidenced by inhibition of cytoplasm-to-nuclear translocation of Smad2/3 and suppression of TGF-ß1-induced upregulation of TGF-ß receptor type I (TGFßRI). Additionally, 3f exhibited potent inhibitory effects against TGF-ß1-induced fibroblasts migration. These data suggested that 3f might be a potential agent for the treatment of idiopathic pulmonary fibrosis via repression of the TGFß/Smad signaling pathway.

Pharmacokinetics of costunolide and dehydrocostuslactone after oral administration of Radix aucklandiae extract in normal and gastric ulcer rats.

Costunolide and dehydrocostuslactone are the main active ingredients of Radix Aucklandiae (RA). An accurate and sensitive LC-MS/MS method was established to simultaneously determine contents of costunolide and dehydrocostuslactone in plasma. There were significant differences in pharmacokinetic parameters (AUC0-t, Cmax,1, Cmax,2, Tmax,1, Vd, and CL) of costunolide and dehydrocostuslactone between RA group and costunolide group or dehydrocostuslactone group. The relative bioavailability of costunolide or dehydrocostuslactone of RA extract was improved. As compared to normal group, the Tmax,2 values of dehydrocostuslactone of RA in gastric ulcer group were prolonged, while the Cmax,1, Cmax,2, and AUC0-t values decreased.

Chemical profiling of Di-Wu-Yang-Gan Granules by ultra performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry with MSE technology.

Di-Wu-Yang-Gan Granules is a Traditional Chinese Medicine prescription used for the treatment of HBeAg-negative chronic hepatitis B patients in China. It consists of five commonly used Chinese herbs. However, the chemical constituents of the whole prescription had not been clarified yet. Hence, in this study, the chemical profiling of Di-Wu-Yang-Gan Granules was explored by ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, which can provide accurate molecular weight within 5-ppm error and sufficient MS/MS fragment ions without the need for precursor ion selection. As a result, 116 compounds were identified, including lignans, triterpenesaponins, flavonoids, coumarins, iridoids, nortriterpenoids, phenolic acids, and sesquiterpenes. All compounds were further assigned to the individual herbs. In conclusion, this established method was reliable and effective for the separation and identification of the constituents in Di-Wu-Yang-Gan Granules. The findings are beneficial for quality control of the prescription during production and provide helpful chemical information for exploring its efficacy and the mechanism of action. The fragmentation regularity summarized in this study also provided important information for the rapid identification of the chemical composition in herbal medicines or their prescription.

Three New Highly Oxygenated Germacranolides from Carpesium Divaricatum and Their Cytotoxic Activity.

Three new highly oxygenated (2⁻4), and two known (1 and 5) germacranolides, were isolated from the whole plant of Carpesium divaricatum. The planar structures and relative configurations of the new compounds were determined by detailed spectroscopic analysis. The absolute configuration of 1 was established using the circular dichroism (CD) method and X-ray diffraction, and the stereochemistry of the new compounds 2⁻4 were determined using similar CD spectra with 1. The new compound 2 and the known compound 5 exhibited potent cytotoxicity against hepatocellular cancer (Hep G2) and human cervical cancer (HeLa) cells, superior to those of the positive control cis-platin.

The evaluations of 99mTc cyclopentadienyl tricarbonyl triphenyl phosphonium cation for multidrug resistance.

A triphenylphosphonium cation, [99mTc]Technetium cyclopentadienyltricarbonyl-6-hexanoyl-triphenylphosphonium cation ([99mTc]3) was prepared to target multidrug resistance (MDR). The radiotracer was evaluated in the MDR-negative MCF-7 and MDR-positive MCF-7/ADR cell lines in vitro, as well as animal models in vivo. [99mTc]3 was proofed to be a substrate of P-glycoprotein and multidrug resistant protein 1, and showed a higher accumulation in the MDR-negative MCF-7 cells compared to 99mTc-sestamibi in vitro. The MCF-7 tumor-to-MCF-7/ADR tumor ratio of [99mTc]3 was ∼3 at 1hp.i. in the biodistribution study. These results demonstrated the capability of the radiotracer to detect multidrug resistance in tumor cells.

18F-Labeled indole-based analogs as highly selective radioligands for imaging sigma-2 receptors in the brain.

We have designed and synthesized a series of indole-based σ2 receptor ligands containing 5,6-dimethoxyisoindoline or 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline as pharmacophore. In vitro competition binding assays showed that all ten ligands possessed low nanomolar affinity (Ki=1.79-5.23nM) for σ2 receptors and high subtype selectivity (Ki (σ2)/Ki (σ1)=56-708). Moreover, they showed high selectivity for σ2 receptor over the vesicular acetylcholine transporter (>1000-fold). The corresponding radiotracers [18F]16 and [18F]21 were prepared by an efficient one-pot, two-step reaction sequence with a home-made automated synthesis module, with 10-15% radiochemical yield and radiochemical purity of >99%. Both radiotracers showed high brain uptake and σ2 receptor binding specificity in mice.

Trichoderpyrone, a Unique Polyketide Hybrid with a Cyclopentenone-Pyrone Skeleton from the Plant Endophytic Fungus Trichoderma gamsii.

Trichoderpyrone (1), a unique polyketide with a cyclopentenone-pyrone hybrid skeleton, was isolated from the plant endophytic fungus Trichoderma gamsii. The structure of 1 was determined by detailed analysis of NMR data together with comparison of chemical shift values of similar fragments. The relative and absolute configurations were established by NOESY correlations and CD experiment. Trichoderpyrone (1) displayed weak cytotoxic activities against A549, HepG2, and HeLa cancer cell lines. 1 might originate from a hybrid biosynthetic pathway through two nonreduced (NR) polyketide megasynthetases.

The Effect of Chinese Herbal Medicine Formula mKG on Allergic Asthma by Regulating Lung and Plasma Metabolic Alternations.

Asthma is a chronic inflammatory disorder of the airway and is characterized by airway remodeling, hyperresponsiveness, and shortness of breath. Modified Kushen Gancao Formula (mKG), derived from traditional Chinese herbal medicines (TCM), has been demonstrated to have good therapeutic effects on experimental allergic asthma. However, its anti-asthma mechanism remains currently unknown. In the present work, metabolomics studies of biochemical changes in the lung tissue and plasma of ovalbumin (OVA)-induced allergic asthma mice with mKG treatment were performed using ultra high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). Partial least squares-discriminate analysis (PLS-DA) indicated that the metabolic perturbation induced by OVA was reduced after mKG treatment. A total of twenty-four metabolites involved in seven metabolic pathways were identified as potential biomarkers in the development of allergic asthma. Among them, myristic acid (L3 or P2), sphinganine (L6 or P4), and lysoPC(15:0) (L12 or P16) were detected both in lung tissue and plasma. Additionally, l-acetylcarnitine (L1), thromboxane B2 (L2), 10-HDoHE (L10), and 5-HETE (L11) were first reported to be potential biomarkers associated with allergic asthma. The treatment of mKG mediated all of those potential biomarkers except lysoPC(15:0) (P16). The anti-asthma mechanism of mKG can be achieved through the comprehensive regulation of multiple perturbed biomarkers and metabolic pathways.

LncRNA and mRNA expression profiles of glioblastoma multiforme (GBM) reveal the potential roles of lncRNAs in GBM pathogenesis.

Glioblastoma multiforme (GBM) is the most common brain malignancy. Long non-coding RNAs (lncRNAs) are aberrantly expressed in many cancers and are involved in their cell proliferation, apoptosis, angiogenesis, and invasion. The functional roles of lncRNAs in GBM are less known. We analyzed a cohort of exon microarray datasets from The Cancer Genome Atlas. The differently expressed lncRNAs and mRNA were subjected to construct lncRNA-mRNA co-expression network. Probable functions for lncRNAs were predicted according to lncRNA-mRNA network and genomic adjacency by GO and pathway analysis. The expression of lncRNAs and mRNAs in GBM tissues versus normal brain tissues was examined by quantitative reverse transcription polymerase chain reaction. The 398 lncRNAs and 1995 mRNAs were identified as distinctively expressed in GBM. Probable functional roles for 98 lncRNAs were involved in 30 pathways and 32 gene functions related to tumorigenesis, development, and metastasis. The identified sets of key lncRNAs specific to GBM were subsequently verified by experiment in GBM tissues. Our reports predict the biological functions of a multitude of lncRNAs in GBM that could be potential diagnostic and prognostic biomarkers as well as therapeutic targets. Moreover, our research provides a road map for the identification and analysis of lncRNAs in tumors.