Metabolomics for Clinical Biomarker Discovery and Therapeutic Target Identification.

As links between genotype and phenotype, small-molecule metabolites are attractive biomarkers for disease diagnosis, prognosis, classification, drug screening and treatment, insight into understanding disease pathology and identifying potential targets. Metabolomics technology is crucial for discovering targets of small-molecule metabolites involved in disease phenotype. Mass spectrometry-based metabolomics has implemented in applications in various fields including target discovery, explanation of disease mechanisms and compound screening. It is used to analyze the physiological or pathological states of the organism by investigating the changes in endogenous small-molecule metabolites and associated metabolism from complex metabolic pathways in biological samples. The present review provides a critical update of high-throughput functional metabolomics techniques and diverse applications, and recommends the use of mass spectrometry-based metabolomics for discovering small-molecule metabolite signatures that provide valuable insights into metabolic targets. We also recommend using mass spectrometry-based metabolomics as a powerful tool for identifying and understanding metabolic patterns, metabolic targets and for efficacy evaluation of herbal medicine.

Microbial community evolution and individual-based model validation of biofilms in single-stage partial nitrification/anammox system.

In this study, matrix degradation, microbial community development, and distribution using an individual-based model during biofilm formation on carriers at varying depths within a single-stage partial nitrification/anammox system were simulated. The findings from the application of individual-based model fitting, fluorescence in situ hybridization, and high-throughput sequencing reveal the presence of aerobic bacteria, specifically ammonia-oxidizing bacteria, as discrete particles within the outer layer of the carrier. Facultative anaerobic bacteria exemplified by anaerobic ammonia-oxidizing bacteria, are observed as aggregates within the middle layer. Conversely, anaerobic bacteria, represented by denitrifiers, are enveloped by extracellular polymeric substances within the inner layer. The present study extends the application of individual-based model to the formation of polyurethane-supported biofilms and presents valuable avenues for the design and advancement of pragmatic engineering carriers.

Tactile Features of Human Finger Contact Motor Primitives.

The human hand interacts with the environment via physical contact, and tactile information is closely associated with finger movement patterns. Studying the relationship between motor primitives of the finger and the corresponding tactile feedback provides valuable insight into the nature of touch and informs the simulation of humanoid tactile. This research decomposed finger contact into three fundamental motor primitives: contact-on, stick-to-slip, and full slip, then examined the tactile features associated with each motor primitive, including the center of mass (COM) and the centroid of the contact pressure distribution matrix and the total contact area. The change in fingertip contact area during contact-on was in accordance with a first-order kinetic model. In the stick-to-slip, there was a generalized linear relationship between the fingertip skin stretch and the magnitude of the tangential force. Moreover, the skin stretch of the fingertip mirrored the direction of the motion. During the full slip, the COM's movement effectively represented the direction of the tangential force, with an error margin of no more than five degrees. Experiments showed that certain fingertip motions can be portrayed, transmitted, and replicated using tactile information. This research opens potential avenues for remote immersive physical communication in robotics and other related fields.

Association between sleep apnoea and risk of cognitive impairment and Alzheimer's disease: a meta-analysis of cohort-based studies.

PURPOSE: To provide updated evidence on the association of obstructive sleep apnoea (OSA)/sleep-disordered breathing (SDB) with risk of all-cause cognitive impairment/dementia and Alzheimer's disease (AD). METHODS: A systematic literature search was done in PubMed, EMBASE and Scopus databases for cohort studies (retrospective or prospective) that documented the association of SDB/OSA with the risk of cognitive impairment or all-cause dementia or AD. Only studies that were published in the year 2000 and onwards were included. The random-effects model was used for all the analyses and effect sizes were reported as hazards ratio (HR) with 95% confidence intervals. RESULTS: Of 15 studies were included in the meta-analysis, SDB/OSA was diagnosed with at-home polysomnography in six studies, while five studies relied on self-report or questionnaires. In the remaining studies, International Classification of Diseases (ICD) codes determined the diagnosis of SDB. The overall pooled analysis showed that patients with SDB/OSA had higher risk of cognitive impairment and/or all-cause dementia (HR 1.52, 95% CI: 1.32, 1.74), when compared to patients without SDB/OSA. However, when studies with diagnosis of SDB based on polysomnography were pooled together, the strength of association for all-cause cognitive impairment was weaker (HR 1.32, 95% CI: 1.00, 1.74). CONCLUSION: Findings suggest a possible association of SDB/OSA with risk of all-cause cognitive impairment and/or dementia. However, careful interpretation is warranted as the majority of the studies did not rely on objective assessment based on polysomnography.

Combined effect of transcutaneous auricular vagus nerve stimulation and 0.1 Hz slow-paced breathing on working memory.

Background: Previous research has found that transcutaneous auricular vagus nerve stimulation (taVNS) can improve working memory (WM) performance. It has also been shown that 0.1 Hz slow-paced breathing (SPB, i.e., breathing at a rate of approximately 6 breaths/min) can significantly influence physical state and cognitive function via changes in autonomic afferent activity. In the present study, we investigated the synergistic effects of taVNS and SPB on WM performance. Methods: A total of 96 healthy people participated in this within-subjects experiment involving four conditions, namely taVNS, SPB, combined taVNS with SPB (taVNS + SPB), and sham. Each participant underwent each intervention for 30 min and WM was compared pre- and post-intervention using the spatial and digit n-back tasks in a random order four times. Permutation-based analysis of variance was used to assess the interaction between time and intervention. Results: For the spatial 3-back task, a significant interaction between time and intervention was found for the accuracy rate of matching trials (mACC, p = 0.03). Post hoc analysis suggested that both taVNS and taVNS + SPB improved WM performance, however, no significant difference was found in the SPB or sham groups. Conclusion: This study has replicated the effects of taVNS on WM performance reported in previous studies. However, the synergistic effects of combined taVNS and SPB warrant further research.

Transcutaneous auricular vagus stimulation (taVNS) improves human working memory performance under sleep deprivation stress.

Many human activities require high cognitive performance over long periods, while impairments induced by sleep deprivation influence various aspects of cognitive abilities, including working memory (WM), attention, and processing speed. Based on previous research, vagal nerve stimulation can modulate cognitive abilities, attention, and arousal. Two experiments were conducted to assess the efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) to relieve the deleterious effects of sleep deprivation. In the first experiment, 35 participants completed N-back tasks at 8:00 a.m. for two consecutive days in a within-subject study. Then, the participants received either taVNS or earlobe stimulation (active control) intervention in two sessions at random orders after 24 h of sustained wakefulness. Then, they completed the N-back tasks again. In the second experiment, 30 participants completed the psychomotor vigilance task (PVT), and 32 completed the N-back tasks at 8:00 a.m. on the first and second days. Then, they received either taVNS or earlobe stimulation at random orders and finished the N-back and PVT tasks immediately after one hour. In Experiment 1, taVNS could significantly improve the accuracy rate of participants in spatial 3-back tasks compared to active control, which was consistent with experiment 2. However, taVNS did not specifically enhance PVT performance. Therefore, taVNS could be a powerful intervention for acute sleep deprivation as it can improve performance on high cognitive load tasks and is easy to administer.

Impact of regional temperature on the adoption of electric vehicles: an empirical study based on 20 provinces in China.

The development of electric vehicles (EVs) is not only a necessary path for China to move from a big country to a powerful country in automobile industry, but also a strategic measure to achieve the goal of "peak carbon dioxide emissions" and "carbon neutrality." However, in the low and high temperature environment, EVs may face problems such as a large reduction in cruising range, slow charging and poor safety, which decrease the attractiveness of EVs to consumers and hinder the EV adoption. However, existing research rarely pays attention to the impact of temperature on the EV adoption. Based on the panel data of electric vehicle sales in 20 Chinese provinces from 2010 to 2018, this paper uses interaction fixed effect (FE) model to test the effect of temperature on the EV adoption and explains the causes of regional differences in EV adoption. The study has the following findings. Firstly, EV sales show an inverted U-shaped trend with the change of temperature. Secondly, compared to extreme high temperature, extreme low temperature has a greater negative impact on the EV adoption. Thirdly, the negative impact of extreme temperature on battery electric vehicles (BEVs) is greater than that of plug-in hybrid electric vehicles (PHEVs). Finally, temperature will make consumers' behavior adaptive by affecting their expectations. These findings can provide policy makers, department of urban planning and building, EV technology and quality inspection department, non-governmental organizations, and EV manufacturer, aiming at accelerating the market proliferation of EVs, with theoretical basis and targeted insights.

PePYL4 enhances drought tolerance by modulating water-use efficiency and ROS scavenging in Populus.

Drought is one of the major limiting factors in the growth of terrestrial plants. Abscisic acid (ABA) and pyrabactin resistance 1/prabactin resistance-1 like/regulatory components of ABA receptors (PYR/PYL/RCARs) play a key role in response to drought stress. However, the underlying mechanisms of this control remain largely elusive in trees. In this study, PePYL4, a potential ortholog of the PYR/PYL/RCARs gene, was cloned from Populus euphratica. It was localized in the cytoplasm and nucleus, induced by ABA, osmotic and dehydration treatments. To study the potential biological functions of PePYL4, transgenic triploid white poplars (Populus tomentosa 'YiXianCiZhu B38') overexpressing PePYL4 were generated. PePYL4 overexpression significantly increased ABA sensitivity and reduced stomatal aperture. Compared with wild-type plants, transgenic plants had higher water-use efficiency (WUE) and lower transpiration. When exposed to drought stress, PePYL4 overexpression plants maintained higher photosynthetic activity and accumulated more biomass. Moreover, overexpression of PePYL4 improved antioxidant enzyme activity and ascorbate content to accelerate reactive oxygen species scavenging. Meanwhile, upregulation expression of the stress-related genes also contributed to improving the drought tolerance of transgenic plants. In conclusion, our data suggest that PePYL4 is a promising gene target for regulating WUE and drought tolerance in Populus.

Dual GGDEF/EAL-Domain Protein RmcA Controls the Type III Secretion System of Pseudomonas aeruginosa by Interaction with CbrB.

Cyclic diguanylate (c-di-GMP) is a major bacterial secondary signaling molecule that controls a multitude of cellular processes. More than 40 genes encoding diguanylate cyclases and phosphodiesterases have been identified in Pseudomonas aeruginosa, and many of them have been intensively investigated. However, the mechanism through which they achieve signaling specificity remains unclear. Here, we revealed that the absence of the dual GGDEF/EAL-domain protein RmcA significantly affected biofilm formation of P. aeruginosa PAO1 and led to upregulated expression of the type III secretion system (T3SS) genes; overexpression of RmcA strongly reduced the expression of T3SS. Further investigation showed that the regulatory function of RmcA was independent of the Gac/Rsm pathway. To identify the interaction partners of RmcA involved in this process, bacterial two-hybrid library screening was performed. We found that RmcA directly interacts with a two-component response regulator CbrB, which is involved in the regulation of biofilm formation and T3SS expression by RmcA. These findings reveal that the dual-domain GGDEF/EAL protein RmcA could achieve specificity of action through physical interaction with CbrB, which extends understanding the complex regulatory network of the c-di-GMP signaling.

Microsatellite analysis and polymorphic marker development based on the full-length transcriptome of Camellia chekiangoleosa.

Camellia chekiangoleosa is a popular variety of Oil-camellia that has high oil production and ornamental value. Microsatellite (SSR) markers are the preferred tool for the molecular marker-assisted breeding of C. chekiangoleosa. By focusing on the problems of the low development efficiency of polymorphic SSR markers and the lack of available functional markers in Oil-camellia, we identified 97,510 SSR loci based on the full-length transcriptome sequence of C. chekiangoleosa. An analysis of SSR characteristics showed that mononucleotide (51.29%) and dinucleotide (34.36%) SSRs were the main repeat types. The main SSR distribution areas based on proportion covered were ordered as follows: 5'UTR > 3'UTR > CDS. By comparing our data with those in databases such as GO and KEGG, we obtained functional annotations of unigene sequences containing SSR sites. The data showed that the amplification efficiency of the SSR primers was 51.72%, and the development efficiency of polymorphic SSR primers was 26.72%. Experiments verified that dinucleotide and pentanucleotide SSRs located in UTR regions could produce more polymorphic markers. An investigation into the genetic diversity of several C. chekiangoleosa populations also suggested that the developed SSR markers had higher levels of polymorphism. This study will provide a reference and high-quality markers for the large-scale development of functional SSR markers and genetic research in Oil-camellia.

Crosstalk between Depression and Breast Cancer via Hepatic Epoxide Metabolism: A Central Comorbidity Mechanism.

Breast cancer (BC) is a serious global challenge, and depression is one of the risk factors and comorbidities of BC. Recently, the research on the comorbidity of BC and depression has focused on the dysfunction of the hypothalamic-pituitary-adrenal axis and the persistent stimulation of the inflammatory response. However, the further mechanisms for comorbidity remain unclear. Epoxide metabolism has been shown to have a regulatory function in the comorbid mechanism with scattered reports. Hence, this article reviews the role of epoxide metabolism in depression and BC. The comprehensive review discloses the imbalance in epoxide metabolism and its downstream effect shared by BC and depression, including overexpression of inflammation, upregulation of toxic diols, and disturbed lipid metabolism. These downstream effects are mainly involved in the construction of the breast malignancy microenvironment through liver regulation. This finding provides new clues on the mechanism of BC and depression comorbidity, suggesting in particular a potential relationship between the liver and BC, and provides potential evidence of comorbidity for subsequent studies on the pathological mechanism.

Assessing the Effect of Simultaneous Combining of Transcranial Direct Current Stimulation and Transcutaneous Auricular Vagus Nerve Stimulation on the Improvement of Working Memory Performance in Healthy Individuals.

A previous study found that combining transcranial direct current stimulation (tDCS) and transcutaneous auricular vagus nerve stimulation (taVNS) could evoke significantly larger activation on a range of cortical and subcortical brain regions than the numerical summation of tDCS and taVNS effects. In this study, two within-subject experiments were employed to investigate its effects on working memory (WM). In experiment 1, the WM modulatory effects of tDCS over the left dorsolateral prefrontal cortex (DLPFC), taVNS, and simultaneous joint simulation of tDCS over the left DLPFC and taVNS (SJS-L) were compared among 60 healthy subjects. They received these three interventions between the baseline test and post-test in a random manner three times. In spatial 3-back task, there was a significant interaction between time and stimulations in the accuracy rate of matching trials (mACC, p=0.018). MACCs were significantly improved by SJS (p = 0.001) and taVNS (p = 0.045), but not by tDCS (p = 0.495). Moreover, 41 subjects in the SJS group showed improvement, which was significantly larger than that in the taVNS group (29 subjects) and tDCS group (26 subjects). To further investigate the generalization effects of SJS, 72 students were recruited in experiment 2. They received tDCS over the right DLPFC, taVNS, simultaneous joint simulation of tDCS over the right DLPFC and taVNS (SJS-R), and sham stimulation in a random manner four times. No significant results were found, but there was a tendency similar to experiment 1 in the spatial 3-back task. In conclusion, combining tDCS and taVNS might be a potential non-invasive neuromodulation technique which is worthy of study in future.

Towards Understanding PRPS1 as a Molecular Player in Immune Response in Yellow Drum (Nibea albiflora).

Phosphoribosyl pyrophosphate synthetases (EC 2.7.6.1) are key enzymes in the biological synthesis of phosphoribosyl pyrophosphate and are involved in diverse developmental processes. In our previous study, the PRPS1 gene was discovered as a key disease-resistance candidate gene in yellow drum, Nibea albiflora, in response to the infection of Vibrio harveyi, through genome-wide association analysis. This study mainly focused on the characteristics and its roles in immune responses of the PRPS1 gene in yellow drum. In the present study, the NaPRPS1 gene was cloned from yellow drum, encoding a protein of 320 amino acids. Bioinformatic analysis showed that NaPRPS1 was highly conserved during evolution. Quantitative RT-PCR demonstrated that NaPRPS1 was highly expressed in the head-kidney and brain, and its transcription and translation were significantly activated by V. harveyi infection examined by RT-qPCR and immunohistochemistry analysis, respectively. Subcellular localization revealed that NaPRPS1 was localized in cytoplasm. In addition, semi-in vivo pull-down assay coupled with mass spectrometry identified myeloid differentiation factor 88 (MyD88) as an NaPRPS1-interacting patterner, and their interaction was further supported by reciprocal pull-down assay and co-immunoprecipitation. The inducible expression of MyD88 by V. harveyi suggested that the linker molecule MyD88 in innate immune response may play together with NaPRPS1 to coordinate the immune signaling in yellow drum in response to the pathogenic infection. We provide new insights into important functions of PRPS1, especially PRPS1 in the innate immunity of teleost fishes, which will benefit the development of marine fish aquaculture.

Effect of Diet and Exercise-Induced Weight Loss among Metabolically Healthy and Metabolically Unhealthy Obese Children and Adolescents.

Objective: To study the effect of diet- and exercise-based lifestyle intervention on weight loss (WL) and cardiovascular risk among metabolically healthy obese (MHO) and metabolically unhealthy obese (MUO) children and adolescents. Methods: The sample included 282 obese individuals (54% males, age (±SD) 12.9 (±2.3) years) who completed a 3- to 4-week WL camp program between 2017 and 2019. MUO was defined according to the consensus-based definition of pediatric MHO in 2018. Results: The intervention exhibited significantly benefits in improving body weight, body mass index, body fat ratio, waist circumference, systolic blood pressure (SBP), diastolic blood pressure (DBP), resting heart rate (RHR), triglycerides (TG), total cholesterol, and low-density lipoprotein−cholesterol levels in both MHO and MUO groups (for all comparisons, p < 0.01). However, the beneficial high-density lipoprotein−cholesterol (HDL-C) level (both p < 0.01) decreased evidently in both groups after intervention. In addition, percent changes in SBP (p < 0.001), DBP (p < 0.001), RHR (p = 0.025), fasting blood glucose (p = 0.011), and TG (p < 0.001) were more profound in MUO group than that in MHO group. Conclusion: Metabolical health is a mutable and transient state during childhood. Although both groups gained comparable WL benefits from diet- and exercise-based lifestyle intervention, the MUO group may benefit more than the MHO group. Strategies aiming at lowering blood pressure and preventing the decrease of HDL-C level should be considered for the precise treatment of childhood obesity in clinical practice, with the goal of improving metabolically healthy state.

Investigating the Metabolic Mechanisms of Butaselen, An Ebselen Analog.

BACKGROUND: Butaselen is an ebselen analog that is under clinical trials for treating hepatic and pulmonary fibrosis. Our previous studies showed that butaselen is mainly present in human plasma in the form of M2, a free Se-methylated metabolite. OBJECTIVE: This study aimed to investigate the metabolic mechanisms of butaselen. METHODS AND RESULTS: Butaselen was incubated with human plasma. Butaselen immediately disappeared, and the butaselen-HSA (human serum albumin) adduct was detected by HPLC-HRMS, showing that butaselen covalently binds to HSA. The butaselen-HSA adduct was precipitated using acetonitrile and then incubated with PBS, Cys, and GSH for 1 hour. The product was M1, a reduced form of butaselen. The results indicated that HSA, Cys, and GSH can reduce the butaselen-HSA covalent bond. The binding site for butaselen could be the cysteine-34 residue of HSA through pronase and trypsin hydrolysis. Incubating butaselen with cysteine, butaselen-Cys, butaselen-2Cys, and M1 were generated, indicating the covalent binding and reduction of butaselen by cysteine. We incubated liver microsomes and cytosol with butaselen, 6.22 and 246 nM M2 were generated, respectively. The results demonstrated that cytosolic enzymes are mainly involved in M2 production. The amount of M2 in the liver cytosol decreased from 246 nM to 2.21 nM when 10 mM m-anisic acid (a specific TPMT enzyme inhibitor) was added, showing that TPMT is responsible for M2 formation. CONCLUSION: Butaselen was covalently bound to HSA, and the binding site was the cysteine-34 residue of HSA. The butaselen-HSA adduct was reduced by free thiol compounds to generate M1. M1 was further metabolized to M2 by cytosolic TPMT. This study provides a basis for studying the pharmacokinetics of selenium-containing drugs.

Effects of anemia during the third trimester of pregnancy on postpartum depression and pregnancy outcomes in pregnant women older than 35 years: a retrospective cohort study.

BACKGROUND: There is no study on the impact of anemia on postpartum depression and outcomes in mothers older than 35 years, which makes the nursing of these pregnant women with anemia more difficult. METHODS: We retrospectively collected the demographic and clinical characteristics of pregnant women older than 35 years at conception between August 2014 and December 2019. Hemoglobin less than 110 g/L was defined as anemia. Postpartum depression was assessed according to Edinburgh Postnatal Depression Scale. A subgroup analysis was performed by dividing anemia into mild anemia or moderate and severe anemia. All participants were followed up for at least 3 months postpartum and their pregnancy outcomes were recorded. The existence of postpartum depression was evaluated at 4 weeks postpartum. The risk factors of anemia during the third trimester of pregnancy and the impacts of anemia on postpartum depression and pregnancy outcomes were analyzed using multivariable logistic regression analysis. RESULTS: A total of 519 pregnant older than 35 years women were included in this study, including 281 without anemia and 238 with anemia. No significant difference was found in the incidence of postpartum depression between anemia and non-anemia groups (18.9% vs. 12.8%, P=0.057), while the anemia group had significantly higher incidence of preterm delivery, prolonged labor, and caesarean section. The subgroup analysis found that significantly pregnant women with older age in the moderate or severe anemia subgroup had postpartum depression than those in the mild anemia subgroup (23.2% vs. 12.5%, P=0.038). A higher rate of preterm delivery, prolonged labor, and caesarean section was recorded in the moderate or severe anemia subgroup (8.3% vs. 20.4%, P=0.012; 30.2% vs. 43.0%, P<0.001; 20.8% vs. 40.1%, P=0.002). Moderate or severe anemia, the presence of depression during the first trimester of pregnancy, unplanned pregnancy, and fewer parity were identified as risk factors of postpartum depression in pregnant women older than 35 years with anemia. CONCLUSIONS: Anemia has significant impacts on pregnancy outcomes in pregnant women older than 35 years. Furthermore, moderate and severe anemia will significantly increase the incidence of postpartum depression, which should be corrected at an early stage to minimize its negative effects.

Quantification of the major circulating metabolite of BS1801, an ebselen analog, in human plasma.

BS1801 contains two selenium atoms in its structure, which is a specific inhibitor of thioredoxin reductase intended to treat fibrotic interstitial pneumonia (control pulmonary fibrosis) and liver fibrosis. It is currently in phase I clinical trial. However, there was no report about the metabolic transformation and pharmacokinetics of BS1801. In this study, BS1801 metabolites were characterized in the hepatocytes of different species (monkey, dog, mouse, rat, and human) and plasma specimens using the ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC/Q-TOF MS) method. After incubation, BS1801 could not be detected in the hepatocytes of different species and human plasma. Five metabolites were identified based on the characteristic peak clusters of selenium atoms in the mass spectrum, combined with the product ions obtained by MS-MS through collision-induced-dissociation (CID), including M1 (reduction metabolite), M2 (reduction and Se-methylation metabolite), M4 (M2 further oxidized metabolite) and M5 (Se-methylation and Se-glucuronidation conjugation metabolite), of which the amount of M2 was the highest. By comparing the LC-MS information with the synthesized reference substance, the structure of M2 was confirmed. The principal BS1801 metabolic pathways were identified as reduction and Se-methylation in humans. Subsequently, an accurate and fast LC-MS/MS method was established to verify the major metabolite M2 in human plasma. Acetonitrile-induced protein precipitation was employed to extract M2 from human plasma. The metabolite was separated through XDB-C18 (4.6 × 50 mm, 1.8 µm) under isocratic elution with ammonium acetate (5 mM) containing 0.1% formic acid solution (A) and acetonitrile (B) as the mobile phases. A deuterated internal standard for M2 was prepared to overcome the influence of matrix effects during the detection. The bioanalytical method was shown to be precise, specific, accurate, and good linearity over the range of 3.00-3000 ng/mL, and was implemented to assess the pharmacokinetic profiles of M2 in healthy volunteers following a single oral administration of 450 mg BS1801. This is the first-ever study to identify and quantify the major circulating metabolite of ebselen analogs in human plasma.