Coupling the Paternò-Büchi (PB) Reaction With Mass Spectrometry to Study Unsaturated Fatty Acids in Mouse Model of Multiple Sclerosis

Lipid dysregulation has been implicated in multiple sclerosis due to its involvement during and after inflammation. In this study, we have profiled fatty acids (FAs) in the mouse model of multiple sclerosis with new capabilities of assigning carbon-carbon double bond (C=C) location(s) and quantifying C=C location isomers. These new capabilities are enabled by pairing the solution phase Paternò-Büchi (PB) reaction that modifies C=C bonds in FAs, with tandem mass spectrometry (MS/MS), termed as PB-MS/MS. A series of unsaturated FAs and C=C location isomers have been identified, including FA17:1 (Δ10), FA18:1 (Δ9 and Δ11), FA18:2 (Δ9 and Δ12), and FA 20:4 (Δ5, Δ8, Δ11, Δ14). Notable differences in saturated and unsaturated FAs between normal and experimental autoimmune encephalomyelitis (EAE) mice spinal cords have been detected. Furthermore, the effects of hydralazine, a scavenger of acrolein, on profile changes of FAs in mice were studied. Increased Δ11-to-Δ9 isomer ratios for FA 18:1 were noted in the diseased samples as compared to the control. The present work provides a facile and robust analytical method for the quantitation of unsaturated FAs as well as identification of FA C=C location isomers, which will facilitate discovering prospective lipid markers in multiple sclerosis.

Placebo design in WHO-registered trials of Chinese herbal medicine need improvements

BACKGROUND

Physical identical and pharmacological inert are the basic requirements for placebo design, which are essential in clinical trials to evaluate the efficacy of an intervention. However, it is difficult to makeup a placebo of Chinese herbal medicine (CHM) because of special color, taste and smell, etc. Currently, there is no specific requirements and standards for the creation of a CHM-placebo. The purpose of this study is to review the characteristics of the CHM-placebo design and application in registered clinical trials with CHM interventions and identify the common problems, if any.

METHODS

The World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) was systematically searched for CHM interventional trials with placebo-controlled design up to 31 December 2017. Registered information of each included trial was collected from specific registries involved in ICTRP through hyperlinks. Descriptive statistics were used to analyze the characteristics of placebo design in CHM trial registrations.

RESULTS

A total of 889 CHM interventional trials were registered from 1999 to 2017, and 40.8% (363) of them included CHM-placebo control design. The common ways of their design were: placebo as sole control (191, 52.6%); placebo as add-on control with baseline treatment (84, 23.1%); and placebo as double-dummy control (57, 15.7%). Among 363 included trials, 46 (12.7%) reported the compositions of placebos, including CHM ingredients (17 trials), excipients and other agents (29 trials). 2 (0.6%) reported pharmacological inert testing, and 52 (14.3%) descripted their placebos to be physically identical with the CHMs. 14 (3.9%) reported quality control of placebos, and 2 (0.6%) provided blinding assessment of placebos.

CONCLUSIONS

The placebos included in most CHM trial registrations is not optimal in terms of placebo design, application, evaluation and reporting. Specific guidelines or standards of CHM-placebo design, including usage requirements, preparation specifications, quality assessments and reporting guidelines should be developed thus to improve their quality.

Influence of feedstocks and modification methods on biochar's capacity to activate hydrogen peroxide for tetracycline removal

Three types of raw biochar (i.e. CBC, OBC, PBC produced from cornstalk, orange peel and peanut hull, respectively) and the modified ones (i.e., KMnO₄-, KOH- and H₃PO₄-treatment) were employed to activate H₂O₂ for the removal of tetracycline (TC). The effects of pyrolysis temperatures, H₂O₂ concentration and initial pH were examined. TC removal by raw biochars w/o H₂O₂ was dependent on the feedstock and pyrolysis temperature of biochar, but the removal efficiency was still quite low under optimum conditions. The KMnO₄-treatment significantly enhanced the adsorption of TC on all three biochars, but only enhanced the TC removal by CBC + H₂O₂. The KOH-treatment had insignificant effect on the adsorption of TC on biochar, but improved the performance of CBC/PBC + H₂O₂. The H₃PO₄-treatment had a negative impact on TC removal by biochar w/o H₂O₂. Overall, H₂O₂ could either enhance or decrease the TC removal by biochar, depending on biochar type, H₂O₂ concentration and solution pH.

The mitochondrial genome of the black-tailed dasyure (Murexia melanurus)

In this study, we report the mitochondrial genome of the black-tailed dasyure (Murexia melanurus) of New Guinea. The circular genome is 17,736 bp in length and has an AT content of 60.5%. Its gene content – 13 protein-coding genes (PCGs), 2 ribosomal (rRNA) genes, 21 transfer RNA (tRNA) genes, a tRNA pseudogene (tRNA^Lys), and a non-coding control region (CR) – and gene arrangement are consistent with previous marsupial mitogenome assemblies.

Distinct evolution of toll-like receptor signaling pathway genes in cetaceans

BACKGROUND

The relatively rapid spread and diversity of marine pathogens posed an initial and ongoing challenge for cetaceans (whales, dolphins, and porpoises), descendants of terrestrial mammals that transitioned from land to sea approximately 56 million years ago. Toll-like receptors (TLRs) play important roles in regulating immunity against pathogen infections by detecting specific molecular patterns and activating a wide range of downstream signaling pathways. The ever-increasing catalogue of mammalian genomes offers unprecedented opportunities to reveal genetic changes associated with evolutionary and ecological processes.

OBJECTIVE

This study aimed to explore the molecular evolution of TLR signaling pathway genes in cetaceans.

METHODS

Genes involved in the TLR signaling pathway were retrieved by BLAST searches using human coding sequences as queries. We tested each gene for positive selection along the cetacean branches using PAML and Hyphy. Physicochemical property changes of amino acids at all positively selected residues were assessed by TreeSAAP and visualized with WebLogo. Bovine and dolphin TLR4 was assessed using human embryonic kidney cell line HEK293, which lacks TLR4 and its co-receptor MD-2.

RESULTS

We demonstrate that eight TLR signaling pathway genes are under positive selection in cetaceans. These include key genes in the response to Gram-negative bacteria: TLR4, CD14, and LY96 (MD-2). Moreover, 41 out of 65 positively selected sites were inferred to harbor substitution that dramatically changes the physicochemical properties of amino acids, with most of them situated in or adjacent to functional regions. We also found strong evidence that positive selection occurred in the lineage of the Yangtze finless porpoise, likely reflecting relatively recent adaptions to a freshwater milieu. Species-specific differences in TLR4 response were observed between cetacean and terrestrial species. Cetacean TLR4 was significantly less responsive to lipopolysaccharides from a terrestrial E. coli strain, possibly a reflection of the arms race of host-pathogen co-evolution faced by cetaceans in an aquatic environment.

CONCLUSION

This study provides further impetus for studies on the evolution and function of the cetacean immune system.

Rack1 mediates tyrosine phosphorylation of Anxa2 by Src and promotes invasion and metastasis in drug-resistant breast cancer cells

Background

Acquirement of resistance is always associated with a highly aggressive phenotype of tumor cells. Recent studies have revealed that Annexin A2 (Anxa2) is a key protein that links drug resistance and cancer metastasis. A high level of Anxa2 in cancer tissues is correlated to a highly aggressive phenotype. Increased Anxa2 expression appears to be specific in many drug-resistant cancer cells. The functional activity of Anxa2 is regulated by tyrosine phosphorylation at the Tyr23 site. Nevertheless, the accurate molecular mechanisms underlying the regulation of Anxa2 tyrosine phosphorylation and whether phosphorylation is necessary for the enhanced invasive phenotype of drug-resistant cells remain unknown.

Methods

Small interfering RNAs, small molecule inhibitors, overexpression, loss of function or gain of function, rescue experiments, Western blot, wound healing assays, transwell assays, and in vivo metastasis mice models were used to investigate the functional effects of Rack1 and Src on the tyrosine phosphorylation of Anxa2 and the invasion and metastatic potential of drug-resistant breast cancer cells. The interaction among Rack1, Src, and Anxa2 in drug-resistant cells was verified by co-immunoprecipitation assay.

Results

We demonstrated that Anxa2 Tyr23 phosphorylation is necessary for multidrug-resistant breast cancer invasion and metastasis. Rack1 is required for the invasive and metastatic potential of drug-resistant breast cancer cells through modulating Anxa2 phosphorylation. We provided evidence that Rack1 acts as a signal hub and mediates the interaction between Src and Anxa2, thereby facilitating Anxa2 phosphorylation by Src kinase.

Conclusions

Our findings suggest a convergence point role of Rack1/Src/Anxa2 complex in the crosstalk between drug resistance and cancer aggressiveness. The interaction between Anxa2 and Rack1/Src is responsible for the association between drug resistance and invasive/metastatic potential in breast cancer cells. Thus, our findings provide novel insights on the mechanism underlying the functional linkage between drug resistance and cancer aggressiveness.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1147-7) contains supplementary material, which is available to authorized users.

Rack1 mediates Src binding to drug transporter P-glycoprotein and modulates its activity through regulating Caveolin-1 phosphorylation in breast cancer cells

The failure of chemotherapy and the emergence of multidrug resistance (MDR) are the major obstacles for effective therapy in locally advanced and metastatic breast cancer. Overexpression of the drug transporter P-glycoprotein (P-gp) in cancer cells is one of the main causes of MDR due to its ability to efflux anticancer drugs out of cells. Although the signaling node that regulates the expression of P-gp has been intensively investigated; the regulatory mechanism underlying P-gp transport activity remains obscure. Herein, we reported that Rack1 and tyrosine kinase Src confer drug resistance through modulating the transport function of P-gp without altering its protein level. We provide evidences that Rack1 and Src regulate P-gp activity by modulating caveolin-1 (Cav1) phosphorylation. Importantly, Rack1 acts as a signaling hub and mediates Src binding to P-gp, thereby facilitating the phosphorylation of Cav1 by Src and abolishing the inhibitory effect of Cav1 on P-gp. Taken together, our results demonstrate the pivotal roles of Rack1 and Src in modulating P-gp activity in drug-resistant cells. Our findings also provide novel insights into the mechanism regulating P-gp transport activity. Rack1 may represent a new target for the development of effective therapies for reversing drug resistance.

Divergent Evolution of TRC Genes in Mammalian Niche Adaptation

Mammals inhabit a wide variety of ecological niches, which in turn can be affected by various ecological factors, especially in relation to immunity. The canonical TRC repertoire (TRAC, TRBC, TRGC, and TRDC) codes C regions of T cell receptor chains that form the primary antigen receptors involved in the activation of cellular immunity. At present, little is known about the correlation between the evolution of mammalian TRC genes and ecological factors. In this study, four types canonical of TRC genes were identified from 37 mammalian species. Phylogenetic comparative methods (phyANOVA and PGLS) and selective pressure analyses among different groups of ecological factors (habitat, diet, and sociality) were carried out. The results showed that habitat was the major ecological factor shaping mammalian TRC repertoires. Specifically, trade-off between TRGC numbers and positive selection of TRAC and the balanced evolutionary rates between TRAC and TRDC genes were speculated as two main mechanisms in adaption to habitat and sociality. Overall, our study suggested divergent mechanisms for the evolution of TRCs, prompting mammalian immunity adaptions within diverse niches.

Alterations in the gut microbiome and metabolism with coronary artery disease severity

BACKGROUND

Coronary artery disease (CAD) is associated with gut microbiota alterations in different populations. Gut microbe-derived metabolites have been proposed as markers of major adverse cardiac events. However, the relationship between the gut microbiome and the different stages of CAD pathophysiology remains to be established by a systematic study.

RESULTS

Based on multi-omic analyses (sequencing of the V3-V4 regions of the 16S rRNA gene and metabolomics) of 161 CAD patients and 40 healthy controls, we found that the composition of both the gut microbiota and metabolites changed significantly with CAD severity. We identified 29 metabolite modules that were separately classified as being positively or negatively correlated with CAD phenotypes, and the bacterial co-abundance group (CAG) with characteristic changes at different stages of CAD was represented by Roseburia, Klebsiella, Clostridium IV and Ruminococcaceae. The result revealed that certain bacteria might affect atherosclerosis by modulating the metabolic pathways of the host, such as taurine, sphingolipid and ceramide, and benzene metabolism. Moreover, a disease classifier based on differential levels of microbes and metabolites was constructed to discriminate cases from controls and was even able to distinguish stable coronary artery disease from acute coronary syndrome accurately.

CONCLUSION

Overall, the composition and functions of the gut microbial community differed from healthy controls to diverse coronary artery disease subtypes. Our study identified the relationships between the features of the gut microbiota and circulating metabolites, providing a new direction for future studies aiming to understand the host-gut microbiota interplay in atherosclerotic pathogenesis.

[A cross-sectional study on the association between frailty and muscular performances in hospitalized elder patients with coronary artery disease]

Objective: To explore the association between frailty and muscle performances of hospitalized elder adults with coronary artery disease. Methods: A total of 122 hospitalized patients aged 65-85 years old with coronary artery disease from Department of Geriatrics and Cardiology, Peking Union Medical College Hospital between December 2017 and March 2018 were enrolled in the study. A comprehensive geriatric assessment was performed to evaluate existing comorbidity and geriatric syndromes of the patients. Frailty was assessed using the Clinical Fraity Scale. The patients were classified as frail and non-frail, according to the scale. Muscle performances were assessed using grip strength, gait speed, etc. Whole body and appendicular skeletal muscle mass was detected with bioelectrical impedance analysis in patients with reduced grip strength or slowed gait speed. Appendicular skeletal muscle index (ASMI) was calculated. Results: Among all subjects, 28 were with frailty (23.0%) and 94 were without (77.0%). The frail patients were older [(76.7±5.4) years vs. (72.2±5.6)years], had higher Charlson comorbidity index [2.0(1.0,2.75)vs. 1.0(0,2.0)], and higher proportion of malnutrition (14.29% vs. 1.06%), urinary incontinence (39.29% vs. 15.96%), using walking-aid (28.57% vs. 6.38%), and more kinds of taken drugs (8.1±3.0 vs. 6.6±2.7), than the non-frail patients. Prealbumin levels [(207.8±60.0)mg/L vs.(234.3±45.4)mg/L] were lower, and highly sensitive C-reactive protein levels [(5.89±9.57)mg/L vs.(1.89±2.49)mg/L] were higher in the frail patients than in the non-frail patients (all P<0.05). Compared with non-frail patients, the frail patients had poorer grip strength [(19.67±7)kg vs.(29.23±8.29)kg] and slower gait speed [(0.54±0.2)m/s vs.(0.91±0.22)m/s] (all P<0.001). Spearman rank correlation analyses showed that grip strength was positively correlated with the appendicular skeletal muscle mass(r=0.811), whole body skeletal muscle mass(r=0.74) and the ASMI (r=0.783), respectively. Conclusions: The incidence of frailty among hospitalized older adults with coronary artery disease is high. Poor muscle performances were common in these patients. Assessment of frailty and muscle performances can help to evaluate the overall function of older adults with cardiovascular disease in a comprehensive way.

Substrate-Independent Coating with Persistent and Stable Antifouling and Antibacterial Activities to Reduce Bacterial Infection for Various Implants

Implantation of biomedical devices accompanying infections has caused severe problems to public health that require feasible solutions. In this study, a simple approach is reported to fabricate a antimicrobial and antifouling dual-functional coating. This coating consists of a substrate-independent layer-by-layer (LBL) film formed by poly (diallyldimethylammonium) (PDDA) and poly (styrenesulfonate) (PSS), where parts of PSS and PDDA are physically substituted by hetero-bifunctional polyethylene glycol (PEG) ending with a carboxyl group and antimicrobial peptide (ε-Poly-l-lysine, ε-PL). This design (ε-PL-PEG-(PDDA/PSS)9 coating) exhibits not only potent antimicrobial activity against Gram-positive/negative bacteria but also superior antifouling activity on various substrates, including glass and plastic. Moreover, the antifouling and antibacterial performance can be maintained for a longer period of time under physiological environments even after physical damage of the surface due to the homogeneous interspersion and free migration of ε-PL-PEG-COOH in the LBL film. This allows the supplement of these molecules to the surface against molecule loss during usage. Both in vitro and in vivo (rodent subcutaneous infection model) studies show obvious reduction of the bacteria on the coated substrate and in the surrounding tissues with up to 3.2-log reduction, even after repeated usage. The inflammation around the implantation area is also significantly inhibited.

C-reactive protein for predicting cardiovascular and all-cause mortality in type 2 diabetic patients: A meta-analysis

AIMS

There is interest in using blood C-reactive protein (CRP) to predict adverse prognosis outcomes patients with type 2 diabetes. This meta-analysis aimed to investigate the association between elevated baseline CRP level and unfavorable outcomes in type 2 diabetes patients.

MATERIALS/METHODS

PubMed and Embase databases were systematically searched for studies on the association of elevated baseline CRP level with cardiovascular mortality and all-cause mortality from their inception to July 2018. Pooled risk ratio (RR) with 95% confidence intervals (CI) was calculated for the highest versus the lowest CRP level.

RESULTS

Six prospective cohort studies and two post hoc analyses of randomized controlled trials involving 22,322 type 2 diabetes patients were included. Meta-analysis indicated that type 2 diabetes patients with the highest CRP level had a greater risk of all-cause mortality (RR 2.03; 95% CI 1.49-2.75) and cardiovascular mortality (RR 1.76; 95% CI 1.46-2.13). Subgroups analysis indicated that the increased cardiovascular and all-cause mortality risk was consistently found in different study design, follow-up duration or patients with or without cardiovascular risk/established cardiovascular disease subgroups.

CONCLUSIONS

This meta-analysis indicates that elevated baseline serum CRP level is independently associated with future cardiovascular and all-cause mortality in type 2 diabetes patients.

Quality assessment of clinical trial registration with traditional Chinese medicine in WHO registries

OBJECTIVE

This study aimed to assess the registration quality of clinical trials (CTs) with traditional Chinese medicine (TCM) in the WHO International Clinical Trials Registry Platform (ICTRP) and identify the common problems if any.

METHODS

The ICTRP database was searched for all TCM CTs that were registered up to 31 December 2017. Registered information of each trial was collected from specific registry involved in ICTRP through hyperlink. The primary analysis was to assess the reporting quality of registered trials with TCM interventions, which is based on the minimum 20 items of WHO Trial Registration Data Set (TRDS, V.1.2.1) plus optional additional three items recommended by ICTRP, and some specific items for TCM information (including TCM intervention, diagnosis, outcome and rationale). Descriptive statistics were additionally used to analyse the baseline characteristics of TCM trial registrations.

RESULTS

A total of 3339 records in 15 registries were examined. The number of TCM registered trials has increased rapidly after the requirement of mandatory trial registration proposed by International Committee of Medical Journal Editors on 1 July 2005, and the top two registries were Chinese Clinical Trial Registry and ClincialTrials.gov. Of 3339 trials, 61% were prospective registration and 12.8% shared resultant publications. There were 2955 interventional trials but none of them had a 100% reporting rate of the minimum 20 items and additional three items. The reporting quality of these 23 items was not optimal due to 11 of them had a lower reporting rate (<65%). For TCM details, 49.2% lacked information on description of TCM intervention(s), 85.9% did not contain TCM diagnosis criteria, 92.6% did not use TCM outcome(s) and 67.1% lacked information on TCM background and rationale.

CONCLUSION

The registration quality of TCM CTs should be improved by prospective registration, full completion of WHO TRDS, full reporting of TCM information and results sharing. Further full set of trial registration items for TCM trials should be developed thus to standardise the content of TCM trial registration.

Widespread positive selection on cetacean TLR extracellular domain

Toll like receptors (TLRs), key members of innate immune system, can recognize a wide diversity of pathogens and initiate both innate and adaptive immune responses in vertebrate. Cetaceans must have faced new challenges of pathogens when their terrestrial relatives transitioned from the terrestrial to aquatic environment. Here, we sequenced the extracellular domain (ECD) of 10 TLRs in cetacean lineages because this region involved in the recognition of pathogens. A total of 148 sites ranging between 5-26 codons (0.01%-4.83%) were identified to be robust candidates of positive selection at the ECD of 10 TLRs. In addition, the majority (90.54%) of these positively selected codons were found to have radical amino acid changes, which strengthen the evidence of positive selection. Importantly, more radical amino acid changes in selected sites were enriched in the period of early evolutionary transition from land to semi-aquatic and from semi-aquatic to full-aquatic habitat, which might endow cetaceans with a faster adaptation to new pathogens as they transitioned into novel habitat. Interestingly, similar selective intensity was detected in both viral and non-viral TLRs in cetaceans, which was not in line with previous studies on primates and birds that reported stronger positive selection in non-viral TLRs than in viral TLRs. This result may be explained by the fact that cetaceans might have faced diversity of bacteria and viruses during its transitions from terrestrial to aquatic environment whereas both primates and birds probably being affected by only a restricted number of related viruses due to their homogeneous habitat.

Low-Weight 3D Al2 O3 Network as an Artificial Layer to Stabilize Lithium Deposition

Lithium metal has been regarded as an ideal anode for high-energy-density batteries. However, safety and efficiency concerns still linger due to dendrite formation, reactions between the liquid electrolyte and lithium, high resistance with lithium metal, and the weight of interface layer. A new nanometer-thick, hollow, Al₂ O₃ fiber network with an elastic and porous 3D structure has been prepared through an atomic-layer deposition process by using cotton sacrificial templates. Through a comparison study of the lithium deposition behavior by employing artificial layers with different structures, the low-weight 3D layer with lithiophilic properties overcomes the issues resulting from the 2D rigid Al₂ O₃ layer and provides a low overpotential and dendrite-free growth of lithium metal. Moreover, stable lithium deposition enables Li-Li symmetric cells with a 3D artificial layer to be stably cycled 300 times in carbonate-based electrolyte, with superior rate capability, and with a LiNi_1/3 Co_1/3 Mn_1/3 O₂ cathode.