Publications by authors named "Zongwei Cai"

465 Publications

Discovery of emerging sulfur-containing PAHs in PM: Contamination profiles and potential health risks.

J Hazard Mater 2021 Apr 1;416:125795. Epub 2021 Apr 1.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China. Electronic address:

We reported the discovery and identification of emerging sulfur-containing polycyclic aromatic hydrocarbons, namely polycyclic aromatic sulfur heterocycles (PASHs), in PM collected from two typical regions of China, Taiyuan and Guangzhou. Until now, there is no research on contamination status, sources and potential health risks of this unexpected group of organic contaminants in PM. High atmospheric concentrations (ngm) and significant time-dependent variations were determined in PM of Taiyuan from 2017 to 2018. Coal combustion/secondary formation and traffic emission/secondary formation were apportioned as possible pollution sources for the PM-bound PASHs in Taiyuan and Guangzhou, respectively. Dithiothreitol and cell viability assays were applied for evaluations of PASH-induced reactive oxygen species (ROS) production and cell toxicity based on the determined real exposure levels for adults. The results illustrated that PASHs in PM possibly caused oxidative stress and inhibition of human bronchial epithelial cells in seriously polluted regions such as Taiyuan, suggesting that the pollutant-induced health concerns may need more investigations. This study provides new insights into PM pollution, and is beneficial for the development of effective contamination control strategies and reduction of risks on public health.
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http://dx.doi.org/10.1016/j.jhazmat.2021.125795DOI Listing
April 2021

Ambient air PM exposure induces heart injury and cardiac hypertrophy in rats through regulation of miR-208a/b, α/β-MHC, and GATA4.

Environ Toxicol Pharmacol 2021 Mar 31;85:103653. Epub 2021 Mar 31.

Institute of Environmental Science, Shanxi University, Taiyuan, China. Electronic address:

Ambient air fine particulate matter (PM) may increase cardiovascular disease risks. In this study, we investigated the miR-208/GATA4/myosin heavy chain (MHC) regulation mechanisms on cardiac injury in rats after PM exposure via an animal inhalation device. The results showed that PM exposure for 2 months caused pathological heart injury, reduced nucleus-cytoplasm ratio, and increased the levels of CK-MB and cTnI, showing cardiac hypertrophy. Oxidative stress and inflammatory responses were also observed in rats' hearts exposed to PM. Of note, PM exposure for 2-month significantly elevated GATA4 and β-MHC mRNA and protein expression compared with the corresponding controls, along with the high-expression of miR-208b. The ratios of β-MHC/α-MHC expression induced by PM were remarkably raised in comparison to their controls. It suggested that the up-regulation of miR-208b/β-MHC and GATA4 and the conversion from α-MHC to β-MHC may be the important causes of cardiac hypertrophy in rats incurred by PM.
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http://dx.doi.org/10.1016/j.etap.2021.103653DOI Listing
March 2021

Use of NAD tagSeq II to identify growth phase-dependent alterations in RNA NAD capping.

Proc Natl Acad Sci U S A 2021 Apr;118(14)

Department of Biology, Hong Kong Baptist University, Hong Kong SAR, China;

Recent findings regarding nicotinamide adenine dinucleotide (NAD)-capped RNAs (NAD-RNAs) indicate that prokaryotes and eukaryotes employ noncanonical RNA capping to regulate gene expression. Two methods for transcriptome-wide analysis of NAD-RNAs, NAD captureSeq and NAD tagSeq, are based on copper-catalyzed azide-alkyne cycloaddition (CuAAC) click chemistry to label NAD-RNAs. However, copper ions can fragment/degrade RNA, interfering with the analyses. Here we report development of NAD tagSeq II, which uses copper-free, strain-promoted azide-alkyne cycloaddition (SPAAC) for labeling NAD-RNAs, followed by identification of tagged RNA by single-molecule direct RNA sequencing. We used this method to compare NAD-RNA and total transcript profiles of cells in the exponential and stationary phases. We identified hundreds of NAD-RNA species in and revealed genome-wide alterations of NAD-RNA profiles in the different growth phases. Although no or few NAD-RNAs were detected from some of the most highly expressed genes, the transcripts of some genes were found to be primarily NAD-RNAs. Our study suggests that NAD-RNAs play roles in linking nutrient cues with gene regulation in .
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http://dx.doi.org/10.1073/pnas.2026183118DOI Listing
April 2021

Immunometabolism-modulation and immunotoxicity evaluation of perfluorooctanoic acid in macrophage.

Ecotoxicol Environ Saf 2021 Jun 24;215:112128. Epub 2021 Mar 24.

Food Science and Technology Program, Beijing Normal University-Hong Kong Baptist University United International College, Zhuhai, China; State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China. Electronic address:

Perfluorooctanoic acid (PFOA) is one of the most commonly used perfluorinated chemicals in industry. Wide concerns of PFOA toxicity are increased in recent years. However, report on immunotoxicity of PFOA was quite limited. This study aimed to investigate the immunotoxicity of PFOA exposure on macrophage RAW264.7. We assessed the effects of PFOA exposure on macrophage cell viability, cell apoptosis and cellular ROS level, and detected prominent cytokines release by RAW264.7. The results indicated that the cell viability of macrophage RAW264.7 was decreased by PFOA in dose- and time-dependent manners. Specifically, the exposure of 200 μM PFOA significantly increased apoptosis and ROS generation in macrophage, and thus caused cell damage. The ELISA results displayed that 100 μM PFOA exposure induced macrophage activation and enhanced cytokines secretion, including TNF-α, IL-1, IL-6, and IL-12. We also conducted nontargeted metabolomics based on LC-MS/MS and unveiled the perturbed metabolic pathways in macrophages induced by sublethal doses of PFOA (10 μM and 100 μM). Remarkably, global metabolomics results displayed that 10 μM PFOA exposure affected glutamine related pathways and the exposure at 100 μM conspicuously changed glutathione and fatty acid oxidation metabolism. These findings showed that 10 μM PFOA exposure could impel metabolic reprogramming of macrophage to trigger inflammatory response, although such dose displayed no obvious effect on cell viability, cellular ROS or apoptosis events of macrophage RAW264.7.
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http://dx.doi.org/10.1016/j.ecoenv.2021.112128DOI Listing
June 2021

Soluble ACE2-mediated cell entry of SARS-CoV-2 via interaction with proteins related to the renin-angiotensin system.

Cell 2021 Mar 2. Epub 2021 Mar 2.

Department of Clinical Microbiology and Infection Control, The University of Hong Kong-Shenzhen Hospital, Shenzhen, Guangdong Province, China; Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China; Carol Yu Centre for Infection, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China. Electronic address:

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause acute respiratory disease and multiorgan failure. Finding human host factors that are essential for SARS-CoV-2 infection could facilitate the formulation of treatment strategies. Using a human kidney cell line-HK-2-that is highly susceptible to SARS-CoV-2, we performed a genome-wide RNAi screen and identified virus dependency factors (VDFs), which play regulatory roles in biological pathways linked to clinical manifestations of SARS-CoV-2 infection. We found a role for a secretory form of SARS-CoV-2 receptor, soluble angiotensin converting enzyme 2 (sACE2), in SARS-CoV-2 infection. Further investigation revealed that SARS-CoV-2 exploits receptor-mediated endocytosis through interaction between its spike with sACE2 or sACE2-vasopressin via AT1 or AVPR1B, respectively. Our identification of VDFs and the regulatory effect of sACE2 on SARS-CoV-2 infection shed insight into pathogenesis and cell entry mechanisms of SARS-CoV-2 as well as potential treatment strategies for COVID-19.
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http://dx.doi.org/10.1016/j.cell.2021.02.053DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7923941PMC
March 2021

Continuous Dermal Exposure to Triclocarban Perturbs the Homeostasis of Liver-Gut Axis in Mice: Insights from Metabolic Interactions and Microbiome Shifts.

Environ Sci Technol 2021 Mar 10. Epub 2021 Mar 10.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong 999077, China.

Humans are constantly exposed to antimicrobial triclocarban (TCC) via direct skin contact with personal care and consumer products, but the safety of long-term dermal exposure to TCC remains largely unknown. Herein, we used a mouse model to evaluate the potential health risks from the continuous dermal application of TCC at human-relevant concentrations. After percutaneous absorption, TCC circulated in the bloodstream and largely entered the liver-gut axis for metabolic disposition. Nontargeted metabolomics approach revealed that TCC exposure perturbed mouse liver homeostasis, as evidenced by the increased oxidative stress and impaired methylation capacity, leading to oxidative damage and enhancement of upstream glycolysis and folate-dependent one-carbon metabolism. Meanwhile, TCC was transformed in the liver through hydroxylation, dechlorination, methylation, glucuronidation, sulfation, and glutathione conjugation. TCC-derived xenobiotics were subsequently excreted into the gut, and glucuronide and sulfate metabolites could be further deconjugated by the gut microbiota into their active free forms. In addition, microbial community analysis showed that the composition of gut microbiome was altered in response to TCC exposure, indicating the perturbation of gut homeostasis. Together, through tracking the xenobiotic-biological interactions , this study provides novel insights into the underlying impacts of dermally absorbed TCC on the liver and gut microenvironments.
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http://dx.doi.org/10.1021/acs.est.0c08273DOI Listing
March 2021

Trimester-specific and sex-specific effects of prenatal exposure to di(2-ethylhexyl) phthalate on fetal growth, birth size, and early-childhood growth: A longitudinal prospective cohort study.

Sci Total Environ 2021 Feb 28;777:146146. Epub 2021 Feb 28.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China. Electronic address:

Prenatal exposure to di(2-ethylhexyl) phthalate (DEHP) may cause adverse health outcomes. However, trimester-specific impacts of DEHP exposure on offspring growth from fetal to early childhood stage have not been thoroughly evaluated. In this study, participants who provided a full series of urine specimens at three trimesters were selected from a birth cohort conducted at Wuhan, China from 2014 to 2015. 814 mother-offspring pairs were included in the study. Urinary concentrations of DEHP metabolites were determined using liquid chromatography-tandem mass spectrometry. Z-scores for ultrasound-measured fetal growth parameters at 14.0-18.9, 22.6-27.0, and 29.0-33.9 weeks of gestation, were calculated. Weight, height, and body mass index (BMI) at 6, 12, and 24 months were standardized to z-scores using sex-specific and age-specific WHO child growth standards. Linear regressions with generalized estimating equations were used to assess the relationships of DEHP levels per trimester to fetal growth, birth size, and growth at 6, 12, and 24 months to explore the trimester-specific impacts of DEHP exposure on offspring development. Among males, the1-trimester DEHP was negatively related to fetal growth (β < 0, p < 0.05), but positively related to 24-month BMI. The 2nd-trimester DEHP was negatively related to birth weight and birth length, but positively related to weight gain rates from birth to 24 months old. The 3rd-trimester DEHP was positively (β > 0, p < 0.05) associated with birth weight and BMI at 6 and 12 months. Among females, the 1st-trimester DEHP was associated with increased birth length, while the 2nd-trimester DEHP was negatively associated with BMI at 6 and 12 months. A negative association between DEHP and weight gain rates at 6 months was noted among females. This prospective cohort revealed the sex-specific and trimester-specific relationships of DEHP exposure to offspring growth from fetal to early-childhood stage.
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http://dx.doi.org/10.1016/j.scitotenv.2021.146146DOI Listing
February 2021

Data Filtering and Its Prioritization in Pipelines for Spatial Segmentation of Mass Spectrometry Imaging.

Anal Chem 2021 03 8;93(11):4788-4793. Epub 2021 Mar 8.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR 999077, China.

Mass spectrometry imaging (MSI) could provide vast amounts of data at the temporal-spatial scale in heterogeneous biological specimens, which challenges us to segment accurately suborgans/microregions from complex MSI data. Several pipelines had been proposed for MSI spatial segmentation in the past decade. More importantly, data filtering was found to be an efficient procedure to improve the outcomes of MSI segmentation pipelines. It is not clear, however, how the filtering procedure affects the MSI segmentation. An improved pipeline was established by elaborating the filtering prioritization and filtering algorithm. Lipidomic-characteristic-based MSI data of a whole-body mouse fetus was used to evaluate the established pipeline on localization of the physiological position of suborgans by comparing with three commonly used pipelines and commercial SCiLS Lab software. Two structural measurements were used to quantify the performances of the pipelines including the percentage of abnormal edge pixel (PAEP) and CHAOS. Our results demonstrated that the established pipeline outperformed the other pipelines in visual inspection, spatial consistence, time-cost, and robustness analysis. For example, the dorsal pallium (isocortex) and hippocampal formation (Hpf) regions, midbrain, cerebellum, and brainstem on the mouse brain were annotated and located by the established pipeline. As a generic pipeline, the established pipeline could help with the accurate assessment and screening of drug/chemical-induced targeted organs and exploration of the progression and molecular mechanisms of diseases. The filter-based strategy is expected to become a critical component in the standard operating procedure of MSI data sets.
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http://dx.doi.org/10.1021/acs.analchem.0c05242DOI Listing
March 2021

Metabolic and Lipid Alterations in Mice Brain Cortex after PM Exposure.

Chem Res Toxicol 2021 Mar 4. Epub 2021 Mar 4.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR, China.

Fine particulate matter (PM) has been reported to be associated with neurological disorders. However, the effects of PM on changes in metabolic and lipid profile of the brain are unclear. In this study, global metabolomics and lipidomics in mice cortex were investigated from the analyses by ultraperformance liquid chromatography-Orbitrap mass spectrometry. The partial least-squares discriminant analysis showed that the metabolite and lipid profiles were significantly altered by PM exposure. The changed metabolic pathways including alanine, aspartate, and glutamate metabolism, carnitine metabolism, and glycerophospholipid remodeling pathway were found to be associated with a neurodegenerative process according to their corresponding molecular mechanisms. Our results indicated that PM exposure could induce neurological damage.
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http://dx.doi.org/10.1021/acs.chemrestox.1c00015DOI Listing
March 2021

Breast cancer proliferation and deterioration-associated metabolic heterogeneity changes induced by exposure of bisphenol S, a widespread replacement of bisphenol A.

J Hazard Mater 2021 Feb 19;414:125391. Epub 2021 Feb 19.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR, China. Electronic address:

Exposure to bisphenol A (BPA) is considered to be associated with the increased incidence of breast cancer. As a widespread replacement of BPA, the effect of bisphenol S (BPS) on breast tumor programming has not been studied. We reported that BPS exposure significantly promoted proliferation and deterioration of breast tumor by nonmonotonic dose response. The mechanisms were investigated by molecular biology and mass spectrometry-based lipidomics, proteomics and imaging. BPS exposure induced the spatially intratumor heterogeneity of morphology-driven lipids and proteins. The more significant proliferation resulted from BPS-10 (10 μg/kg body weight /day) exposure was evidenced by the variations of spatial distribution of lipids related to ceramide-sphingomyelin signaling pathway, proteins related to chromosomal stability and cell proliferation in central necrotic regions of breast tumor. In contrast, the BPS-100 exposure obviously accelerated deterioration of breast tumor by the variations of spatial distribution of proteins that were associated with the stability of nucleic acid structure in peripheral neoplastic regions. Accordingly, dysregulation of metabolism and protein function as well as DNA methylation and hypoxic tumor microenvironment could be applied to predict the possibility of tumorigenesis, proliferation and metastasis that might be caused by other bisphenol analogs.
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http://dx.doi.org/10.1016/j.jhazmat.2021.125391DOI Listing
February 2021

Squalene Epoxidase Induces Nonalcoholic Steatohepatitis Via Binding to Carbonic Anhydrase 3 and is a Therapeutic Target.

Gastroenterology 2021 Feb 27. Epub 2021 Feb 27.

Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences, CUHK Shenzhen Research Institute, The Chinese University of Hong Kong, Hong Kong, People's Republic of China. Electronic address:

Backgrounds & Aims: Squalene epoxidase (SQLE) is the rate-limiting enzyme for cholesterol biosynthesis. We elucidated the functional significance, molecular mechanisms, and clinical impact of SQLE in nonalcoholic steatohepatitis (NASH).

Methods: We performed studies with hepatocyte-specific Sqle overexpression transgenic (Sqle tg) mice and mice given high-fat high-cholesterol (HFHC) or methionine- and choline-deficient (MCD) diet to induce NASH. SQLE downstream target carbonic anhydrase 3 (CA3) was identified using co-immunoprecipitation and Western Blot. Some mice were given SQLE inhibitor (terbinafine) and CA3 inhibitor (acetazolamide) to study the therapeutic effects in NASH. Human samples (n = 217) including 65 steatoses, 80 NASH, and 72 healthy controls were analyzed for SQLE levels in liver tissue and in serum.

Results: SQLE is highly up-regulated in human NASH and mouse models of NASH. Sqle tg mice triggered spontaneous insulin resistance, hepatic steatosis, liver injury, and accelerated HFHC or MCD diet-induced NASH development. Mechanistically, SQLE tg mice caused hepatic cholesterol accumulation, thereby triggering proinflammatory NF-κB signaling and steatohepatitis. SQLE directly bound to CA3, which induced sterol regulatory element-binding protein 1C activation, acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase1 expression and de novo hepatic lipogenesis. Combined targeting SQLE (terbinafine) and CA3 (acetazolamide) synergistically ameliorated NASH in mice with superior efficacy to either drug alone. Serum SQLE with CA3 could distinguish patients with NASH from steatosis and healthy controls (area under the receiver operating characteristic curve, 0.815; 95% confidence interval, 0.758-0.871).

Conclusions: SQLE drives the initiation and progression of NASH through inducing cholesterol biosynthesis, and SQLE/CA3 axis-mediated lipogenesis. Combined targeting of SQLE and CA3 confers therapeutic benefit in NASH. Serum SQLE and CA3 are novel biomarkers for the noninvasive diagnosis of patients with NASH.
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http://dx.doi.org/10.1053/j.gastro.2021.02.051DOI Listing
February 2021

Integrated Proteomics and Metabolomics Assessment Indicated Metabolic Alterations in Hypothalamus of Mice Exposed to Triclosan.

Chem Res Toxicol 2021 Feb 21. Epub 2021 Feb 21.

State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Hong Kong SAR, China.

Triclosan (TCS) is a ubiquitous antimicrobial used in many daily consumer products. It has been reported to induce endocrine disrupting effects at low doses in mammals, disturbing sex hormone function and thyroid function. The hypothalamus plays a crucial role in the maintenance of neuroendocrine function and energy homeostasis. We speculated that the adverse effects of TCS might be related to the disturbance of metabolic processes in hypothalamus. The present study aimed at investigating the effects of TCS exposure on the protein and metabolite profiles in hypothalamus of mice. Male C57BL/6 mice were orally exposed to TCS at the dosage of 10 mg/kg/d for 13 weeks. The hypothalamus was isolated and processed for mass spectrometry (MS)-based proteomics and metabolomics analyses. The results showed that a 10.6% decrease ( = 0.066) in body weight gain was observed in the TCS exposure group compared with vehicle control group. Differential analysis defined 52 proteins and 57 metabolites that delineated TCS exposed mice from vehicle controls. Among the differential features, multiple proteins and metabolites were found to play vital roles in neuronal signaling and function. Bioinformatics analysis revealed that these differentially expressed proteins and metabolites were involved in four major biological processes, including glucose metabolism, purine metabolism, neurotransmitter release, and neural plasticity, suggesting the disturbance of homeostasis in energy metabolism, mitochondria function, neurotransmitter system, and neuronal function. Our results may provide insights into the neurotoxicity of TCS and extend our understanding of the biological effects induced by TCS exposure.
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http://dx.doi.org/10.1021/acs.chemrestox.0c00514DOI Listing
February 2021

Facile fabrication of magnetic covalent organic frameworks and their application in selective enrichment of polychlorinated naphthalenes from fine particulate matter.

Mikrochim Acta 2021 Feb 18;188(3):91. Epub 2021 Feb 18.

Ministry of Education Key Laboratory of Analytical Science for Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, 350116, Fujian, China.

Magnetic covalent organic frameworks (FeO@TPPCl) were synthesized via a one-pot process in which magnetic nanoparticles (FeO@MNP) served as a magnetic core and 2,4,6-trihydroxy-1,3,5-benzenetricarbaldehyde (TP) and 2,2',5,5'-tetrachlorobenzidine (PCl) as two building blocks to form a shell. The as-prepared FeO@TPPCl nanoparticles have superior features, including large surface area (186.5 m g), high porosity, strong magnetic responsiveness (42.6 emu g), high chlorine content, and outstanding thermal stability, which make them an ideal adsorbent for highly selective enrichment of polychlorinated naphthalenes (PCNs). Combining with atmospheric pressure gas chromatography tandem mass spectrometry (APGC-MS/MS), a simple analytical method of FeO@TPPCl-based magnetic solid-phase extraction (MSPE)-APGC-MS/MS was developed, which exhibited good linearity (r ≥ 0.9991) for eight PCNs in the concentration range 0.1-100 ng L. Moreover, low detection limits (0.005-0.325 ng L), high enrichment factors (46.62-81.97-fold), and good relative standard deviations (RSDs) of inter-day (n = 3, 1.64 to 7.44%) and day-to-day (n = 3, 2.62 to 8.23%) were achieved. This method was successfully applied to the selective enrichment of PCNs in fine particulate matter (PM) samples, and ultra-trace PCNs were found in the range 1.56-3.75 ng kg with satisfactory recoveries (93.11-105.81%). The successful application demonstrated the great potential of FeO@TPPCl nanoparticles as an adsorbent for enrichment of halogenated compounds. Schematic presented one-pot synthesis of magnetic covalent organic framework nanocomposites (FeO@TPPCl) and their application in the selective enrichment of PCNs from PM prior to APGC-MS/MS analysis.
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http://dx.doi.org/10.1007/s00604-021-04750-zDOI Listing
February 2021

Spatial Lipidomics Reveals Anticancer Mechanisms of Bufalin in Combination with Cinobufagin in Tumor-Bearing Mice.

Front Pharmacol 2020 12;11:593815. Epub 2021 Jan 12.

Department of Chemistry, State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Hong Kong, China.

Bufalin (BFL) and cinobufagin (CBF) are the principal bioactive constituents of Chansu, a widely used traditional Chinese medicine (TCM). The synergistic effects of potential active components are responsible for the bioactivities of TCM. Our results showed that the cotreatment with BFL and CBF confers superior anticancer efficacy compared to monotreatment. To reveal the underlying mechanisms of their cotreatment, an integrated method composed of mass spectrometry-based lipidomics and matrix-assisted laser desorption/ionization mass spectrometry imaging was used to delineate the responses of tumor-bearing mice treated with BFL and CBF individually or in combination. The cotreatment with BFL and CBF modulated the sphingolipid metabolism and glycerophospholipid metabolism, and subsequently led to mitochondria-driven apoptosis and systemic disruption of biomembranes in tumor cells. Furthermore, we found that the disturbed lipid markers were mainly located in the non-necrotic tumor areas, the essential parts for the formation of solid tumor framework. Together, our findings revealed what occurred in tumor in response to the treatment of BFL and CBF, from lipids to enzymes, and thus provide insights into the critical role of lipid reprogramming in the satisfactory anticancer effect of BFL in combination with CBF.
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http://dx.doi.org/10.3389/fphar.2020.593815DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883642PMC
January 2021

Evidence of Foodborne Transmission of the Coronavirus (COVID-19) through the Animal Products Food Supply Chain.

Environ Sci Technol 2021 03 16;55(5):2713-2716. Epub 2021 Feb 16.

State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.

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http://dx.doi.org/10.1021/acs.est.0c06822DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7927281PMC
March 2021

Metabolomics reveals the reproductive abnormality in female zebrafish exposed to environmentally relevant levels of climbazole.

Environ Pollut 2021 Apr 5;275:116665. Epub 2021 Feb 5.

Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China; State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong Special Administrative Region, China.

Climbazole (CBZ) ubiquitously detected in the aquatic environment may disrupt fish reproductive function. Thus far, the previous study has focused on its transcriptional impact of steroidogenesis-related genes on zebrafish, but the underlying toxic mechanism still needs further investigation at the metabolic level. In this study, adult zebrafish were chronically exposed to CBZ at concentrations of 0.1 (corresponding to the real concentration in surface water), 10, and 1000 μg/L and evaluated for reproductive function by egg production, with subsequent ovarian tissue samples taken for histology, metabolomics, and other biochemical analysis. After 28 days' exposure, fecundity was significantly decreased in all exposure groups, with the inhibition of oocytes in varying developmental stages to a certain degree. The decrease in retinoic acid and sex hormones, down-regulated genes important in steroidogenesis, and increase in oxidized/reduced glutathione ratio and occurrence of apoptotic cells were observed in zebrafish ovaries following exposure to CBZ even at environmentally realistic concentrations, suggesting that alternations in steroidogenesis and oxidative stress can play significant roles in CBZ-triggered reproductive toxicity. Besides, mass spectrometry imaging analysis validated the results from metabolomics analysis. Our findings provide novel perspectives for unveiling the mechanism of reproductive dysfunction by CBZ and highlight its risk to fish reproduction.
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http://dx.doi.org/10.1016/j.envpol.2021.116665DOI Listing
April 2021

4-Mercaptobenzoic acid as a MALDI matrix for highly sensitive analysis of metals.

Analyst 2021 Mar 10;146(5):1543-1547. Epub 2021 Feb 10.

Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China.

4-Mercaptobenzoic acid (MBA) is introduced as a matrix for laser desorption/ionization time-of-flight mass spectrometry (MS) analysis of metals, exhibiting matrix-interference-free background, greatly enhanced MS signal intensity, and excellent reproducibility. The developed method was successfully extended for the rapid screening and sensitive determination of ultratrace metals in fine particulate matter (PM).
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http://dx.doi.org/10.1039/d1an00022eDOI Listing
March 2021

Convenient detection of HS based on the photothermal effect of Au@Ag nanocubes using a handheld thermometer as readout.

Anal Chim Acta 2021 Mar 12;1149:338211. Epub 2021 Jan 12.

MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, 350116, China.

Hydrogen sulfide (HS), as a hazardous gas, is often found around dump areas. Long term exposure can cause harm to health, it is highly necessary to develop some simple and sensitive methods for on-site HS detection. Herein, a convenient photothermal assay has been designed for the quantitation of HS using a handheld thermometer as readout. Au@Ag nanocubes (Au@Ag NCs), a core-shell nanocomposite with strong light absorption at ∼450 nm, was chosen as a novel photothermal agent in this study. Under the laser irradiation at 450 nm, the Au@Ag NCs show a strong photothermal effect, and a significant temperature enhancement can be measured by the thermometer easily. The presence of HS can lead to the deposition of sulfur onto Au@Ag NCs, altering the localized surface plasmon resonance absorption, size, surface composition, and morphology of Au@Ag NCs and hence leading to the reduction of photothermal effect. The change of the temperature has a linear relationship with the HS concentration in the range of 0.5-80.0 μM with a detection limit of 0.35 μM. By combining with simple sample purification procedures, the developed method has been applied to detect HS in garbage odor gas with satisfactory results.
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http://dx.doi.org/10.1016/j.aca.2021.338211DOI Listing
March 2021

Interaction of mercury ion (Hg) with blood and cytotoxicity attenuation by serum albumin binding.

J Hazard Mater 2021 Jan 23;412:125158. Epub 2021 Jan 23.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR, China. Electronic address:

Blood mercury reflects the amount available from tissues, which is an indication of the exposure level. Here we confirm that Hg caused hemolytic effects at high concentrations; while at light concentrations, most of the ions were bound to human serum albumin (HSA). The binding mechanism of Hg to HSA has been investigated, which indicated that the presence of Hg significantly perturbed the structure of HSA and quenched the fluorescence of protein in a hybrid dynamic and static mode. Hg was preferably bound to cysteine and cystine, where the R‒S‒S‒R structure is responsible for maintaining the protein's structure by stabilizing the α-helical bundles. The metal-protein interaction mitigated the cellular toxicity as concealed by A498 cell lines. The fundamental and comprehensive data in this work is beneficial to elucidating and understanding the identification and binding mechanisms of heavy metals with proteins, as well as possible risks on human beings and the environment.
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http://dx.doi.org/10.1016/j.jhazmat.2021.125158DOI Listing
January 2021

Prenatal exposure to organochlorine pesticides and infant growth: A longitudinal study.

Environ Int 2021 Mar 18;148:106374. Epub 2021 Jan 18.

State Key Laboratory of Environment Health (Incubation), Key Laboratory of Environment and Health, Ministry of Education, Key Laboratory of Environment and Health (Wuhan), Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan 430030, Hubei, China. Electronic address:

Background: The association between exposure to organochlorine pesticides (OCPs) and infant growth has been reported contradictorily in previous studies. Few studies have investigated the effects of prenatal exposure to OCPs on infant growth assessed longitudinally at multiple time points.

Objectives: The purpose of the study was to examine the associations between prenatal exposure to OCPs and infant growth at birth, 6, 12 and 24 months of age, and further to explore the potential sex-specific effects.

Methods: The study population included 1039 mother-infant pairs who participated in a birth cohort study in Wuhan, China. The weight, length and body mass index (BMI) z-score of infants were measured and calculated at birth, 6, 12 and 24 months of age. The overweight status was defined as BMI z-score ≥ 85th percentile according to the standard of World Health Organization. The concentrations of OCPs were measured in cord serum, including hexachlorocyclohexanes (HCHs, consisted of α-HCH, β-HCH, and γ-HCH), p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) and its metabolites: p,p'-dichlorodiphenyldichloroethane (p,p'-DDD), and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE). Generalized linear models were applied to estimate the associations of cord OCPs with infant growth parameters. A group-based semiparametric mixture model was used to estimate growth patterns of infants. Linear-mixed growth curve models were used to examine relationships between predicted growth trajectories and prenatal exposure to OCPs. Weighted quantile sum regression (WQSR) analyses were used to estimate the mixture effects of OCPs on infant growth.

Results: Higher cord serum β-HCH concentrations were associated with higher BMI z-score at 12 [β = 0.07, 95%CI: 0.01, 0.13] and 24 months of age [β = 0.08, 95% CI: 0.02, 0.14]. Similar patterns were observed for relationships of γ-HCH [β = 0.04, 95%CI: 0.01, 0.07] and p,p'-DDT [β = 0.03, 95% CI: 0.00, 0.06] with BMI z-score at 6 and 12 months of age, respectively. However, higher cord serum p,p'-DDE concentrations were associated with a reduction of BMI z-score at 6 months of age [β = -0.07, 95% CI: -0.12, -0.01]. Cord serum β-HCH was also positively associated with the risk of overweight at 12 months of age [RR = 1.16, 95% CI (1.02, 1.33), for the medium vs the lowest tertile]. Among girls, the effects of β-HCH on BMI z-score and overweight status were stronger than boys at 12 and 24 months of age. No statistically significant relationships of other OCPs with infant growth were observed.

Conclusions: Prenatal exposure to β-HCH was associated with increased BMI z-score and higher risk of overweight status in infants especially at 12 and 24 months of age, which seemed to be stronger in girls.
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http://dx.doi.org/10.1016/j.envint.2020.106374DOI Listing
March 2021

Simultaneous determination of methionine cycle metabolites, urea cycle intermediates and polyamines in serum, urine and intestinal tissue by using UHPLC-MS/MS.

Talanta 2021 Mar 5;224:121868. Epub 2020 Nov 5.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, 999077, China. Electronic address:

Metabolites of methionine cycle, urea cycle and polyamine metabolism play important roles in regulating the metabolic processes and the development of diseases. It is rewarding and interesting to monitor the levels of the above metabolites in biological matrices to investigate pathological mechanisms. However, their quantitation is still unsatisfactory due to the poor retention behavior of the analytes on the traditional reversed-phase column. And never a single analytical method simultaneously quantify these three classes of metabolites. Besides, the concentrations of some metabolites are too low to be detected in the biological samples. In this study, we developed a UHPLC-ESI-MS/MS method to simultaneously determine the levels of 14 metabolites, including 4 methionine metabolism metabolites (methionine, homocysteine, S-adenosylmethionine and S-adenosylhomocysteine), 3 urea cycle intermediates (arginine, citrulline and ornithine) and 7 polyamines (putrescine, spermidine, spermine, N-acetylputrescine, N-acetylspermidine, N-acetylspermine and N,N-diacetylspermine). The chromatographic separation was performed on the BEH amide column within 14 min using water and acetonitrile (both with 0.1% formic acid) as the mobile phases. The results of method validation showed good selectivity, linearity (r > 0.99), recovery (93.1%-112.1%), inter-day and intra-day precision (RSD < 13.6% and RSD < 11.0%, respectively), stability (RSD < 15.1%) and matrix effect (76.0%-113.2%). The method is simple, quick and sensitive without derivatization processes and the use of ion-pairing reagents. This approach was successfully applied in urine, serum and tissue matrices, as well as in identifying potential biomarkers for hyperthyroidism and hypothyroidism. The method is promising to provide more information on pathophysiological mechanisms in metabolomics study.
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http://dx.doi.org/10.1016/j.talanta.2020.121868DOI Listing
March 2021

Frequent occurrence of triclosan hydroxylation in mammals: A combined theoretical and experimental investigation.

J Hazard Mater 2021 Apr 9;407:124803. Epub 2020 Dec 9.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, 999077 Hong Kong, China. Electronic address:

Triclosan (TCS) is a widespread antimicrobial agent with many adverse health risks. Its hepatoxicity invariably points to the activation of constitutive androstane receptor (CAR), which regulates cytochrome P450 (CYP) genes that are critical for oxidative metabolism. Here, we provide the theoretical and experimental evidences showing that metabolic activation of TCS frequently occurs through aromatic hydroxylation in mammals. CYP-mediated oxidation was predicted to take place at each aromatic C‒H bond. Molecular docking and in vitro approaches reveal oxidative reaction could be efficiently catalyzed by CAR-regulated CYP2B6 enzyme. Parallel reaction monitoring (PRM) high-resolution mass spectrometry was utilized to identify and profile TCS oxidative metabolites in paired mouse liver, bile, feces, plasma and urine. We found multiple hydroxylated isomers including the products generated via the NIH shift of chlorine, as well as their subsequent conjugates. These metabolites showed isomer-specific retention in mice. Glucuronide conjugates are more readily excreted than the sulfates. Moreover, for the first time, isomeric hydroxylated metabolites were detected in the urine and stool of human subjects used TCS-contained household and personal care products. Collectively, these findings suggest that hydroxylation is an important, yet often underestimated element that worth considering to fully evaluate the biological fates and health risks of TCS.
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http://dx.doi.org/10.1016/j.jhazmat.2020.124803DOI Listing
April 2021

New insights into the cellular mechanism of triclosan-induced dermal toxicity from a combined metabolomic and lipidomic approach.

Sci Total Environ 2021 Feb 1;757:143976. Epub 2020 Dec 1.

Beijing Normal University-Hong Kong Baptist University United International College, Zhuhai, China; State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China. Electronic address:

Triclosan (TCS), an antimicrobial chemical, has been widely used in consumer goods and personal care products. Despite skin is the crucial entry of TCS into human body, previous studies mainly focused on the potential health risks after TCS absorption. Considering in vivo evidences have indicated that topical use of TCS could lead to serious skin lesions, it is thus in urgent need to unveil the underlying mechanisms of dermal toxicity caused by TCS application. In this study, mass spectrometry-based metabolomics and lipidomics were applied to investigate TCS-induced changes of endogenous small molecular metabolites and lipids in human HaCaT keratinocytes. Metabolic biomarker analysis revealed that TCS exposure was associated with the elevation of purine and glutathione metabolism, down-regulation of amino acid metabolism and dysregulation of lipid metabolism in keratinocytes. These intracellular metabolic disorders consequently led to the overproduction of reactive oxygen species (ROS) and accumulation of ammonia. TCS-induced oxidative stress was further validated in human HaCaT cells, functioning as the crucial factor for the generation of pro-inflammatory cytokines that triggered inflammation and lipid disturbances related to cell apoptosis. Our findings update the existing understanding of skin health risks of TCS application at the molecular level.
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http://dx.doi.org/10.1016/j.scitotenv.2020.143976DOI Listing
February 2021

Three-dimensional quantitative mass spectrometry imaging in complex system: From subcellular to whole organism.

Mass Spectrom Rev 2020 Dec 9. Epub 2020 Dec 9.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR, China.

Mass spectrometry imaging (MSI) has been applied for label-free three-dimensional (3D) imaging from position array across the whole organism, which provides high-dimensional quantitative data of inorganic or organic compounds that may play an important role in the regulation of cellular signaling, including metals, metabolites, lipids, drugs, peptides, and proteins. While MSI is suitable for investigation of the spatial distribution of molecules, it has a limitation with visualization and quantification of multiple molecules. 3D-MSI, however, can be applied toward exploring metabolic pathway as well as the interactions of lipid-protein, protein-protein, and metal-protein in complex systems from subcellular to the whole organism through an untargeted methodology. In this review, we highlight the methods and applications of MS-based 3D imaging to address the complexity of molecular interaction from nano- to micrometer lateral resolution, with particular focus on: (a) common and hybrid 3D-MSI techniques; (b) quantitative MSI methodology, including the methods using a stable isotope labeling internal standard (SILIS) and SILIS-free approaches with tissue extinction coefficient or virtual calibration; (c) reconstruction of the 3D organ; (d) application of 3D-MSI for biomarker screening and environmental toxicological research. 3D-MSI quantitative analysis provides accurate spatial information and quantitative variation of biomolecules, which may be valuable for the exploration of the molecular mechanism of the disease progresses and toxicological assessment of environmental pollutants in the whole organism. Additionally, we also discuss the challenges and perspectives on the future of 3D quantitative MSI.
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http://dx.doi.org/10.1002/mas.21674DOI Listing
December 2020

Cumulative health risks for bisphenols using the maximum cumulative ratio among Chinese pregnant women.

Environ Pollut 2021 Feb 20;270:116044. Epub 2020 Nov 20.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR, China. Electronic address:

Bisphenol A and its alternatives are frequently detected in environmental and human samples, but studies associated with the pattern of combined health hazards from the exposure to the bisphenol mixtures are lacking, particularly for pregnant women. Here, we recruited 941 pregnant women with a full set of urine samples in the three trimesters collected under a cohort study project in Wuhan, China, between 2014 and 2015. We measured the concentrations of 8 bisphenols in 2823 urine samples, and calculated the average concentrations of bisphenols, which were detected in over 50% of samples, once during each trimester of pregnancy. We calculated the maximum cumulative ratio (MCR) on basis of estimated daily intake (EDI), hazard quotient (HQ), hazard index (HI) of three major bisphenols, including bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS), to find which one or mixtures drive risks. Participants were categorized into four groups according to their maximum HQ, HI and MCR values. We found negative relationships between log(MCR-1) and log(HI) with the slope (-0.6431). Percentage of HQ of BPA in HI ranged from 37.1% (<25th percentiles of HI) to 75.5% (>95th percentiles of HI) indicating the upward trend of dominance by BPA at increasing HI ranges. The cumulative health risks of bisphenol exposures largely originated from the health hazards of BPA and BPS, particularly BPA. The intervention for regulation on the production and application of BPA and its alternatives are urgent, and China should consider national regulation on these chemicals based on its risk to human health.
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http://dx.doi.org/10.1016/j.envpol.2020.116044DOI Listing
February 2021

Association between urinary organophosphate flame retardant diesters and steroid hormones: A metabolomic study on type 2 diabetes mellitus cases and controls.

Sci Total Environ 2021 Feb 20;756:143836. Epub 2020 Nov 20.

MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China.

Metabolomic analysis was conducted by collecting urine samples from 128 participants in diagnose of type 2 diabetes mellitus (T2DM) and 105 volunteers in healthy condition, in order to identify biomarkers of experimental populations. The urinary concentrations of organophosphate flame retardant (OPFR) diesters were determined and linear regression model was used to find associations between OPFR diesters and the identified biomarkers. The urinary concentrations of OPFR diesters ranged from 0.17-779 μg/g creatinine. Diphenyl phosphate (DPHP) was detected with the highest frequency of 97% at a median level of 1.21 μg/g, and bis(1-chloro-2-propyl) phosphate (BCIPP) dominated the highest median level at 4.24 μg/g with a detection frequency of 94.4%. As compared with the control, the urinary median concentrations of bis(2-butoxyethyl) phosphate (BBOEP), bis(1,3-dichloro-2-propyl) phosphate (BDCPP) and DPHP were 2.76, 2.48, and 1.46 times higher in people with T2DM, respectively. Urinary metabolomic data revealed that steroid synthesis was the most significantly altered metabolic pathway between the case and control population. Two biomarkers of cortisol and cortisone that play an important role in steroid hormone regulation were quantified. The linear regression model indicated that per-quartile range increase in the concentrations of each OPFR diester was associated 18%-41% increase in the concentrations of cortisol and cortisone, which may impact energy metabolism linked with T2DM. To our knowledge, this study for the first time reported the altered levels of steroid hormones associated with urinary OPFR diesters.
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http://dx.doi.org/10.1016/j.scitotenv.2020.143836DOI Listing
February 2021

Corrigendum to 'Effects of PM exposure in utero on heart injury, histone acetylation and GATA4 expression in offspring mice'[Chemosphere, 2020, volume 256, 127133].

Chemosphere 2021 Jan 24;262:128679. Epub 2020 Oct 24.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong. Electronic address:

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http://dx.doi.org/10.1016/j.chemosphere.2020.128679DOI Listing
January 2021

Multilayered glycoproteomic analysis reveals the hepatotoxic mechanism in perfluorooctane sulfonate (PFOS) exposure mice.

Environ Pollut 2021 Jan 27;268(Pt A):115774. Epub 2020 Oct 27.

State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR, China. Electronic address:

Perfluorooctane sulfonate (PFOS) is one of the most widely used and distributed perfluorinated compounds proven to cause adverse health outcomes. Datasets of ecotoxico-genomics and proteomics have given greater insights for PFOS toxicological effect. However, the molecular mechanisms of hepatotoxicity of PFOS on post-translational modifications (PTMs) regulation, which is most relevant for regulating the activity of proteins, are not well elucidated. Protein glycosylation is one of the most ubiquitous PTMs associated with diverse cellular functions, which are critical towards the understanding of the multiple biological processes and toxic mechanisms exposed to PFOS. Here, we exploit the multilayered glycoproteomics to quantify the global protein expression levels, glycosylation sites, and glycoproteins in PFOS exposure and wild-type mouse livers. The identified 2439 proteins, 1292 glycosites, and 799 glycoproteins were displayed complex heterogeneity in PFOS exposure mouse livers. Quantification results reveal that 241 dysregulated proteins (fold change ≥ 2, p < 0.05) in PFOS exposure mouse livers were involved in the lipid and xenobiotic metabolism. While, 16 overexpressed glycoproteins were exclusively related to neutrophil degranulation, cellular responses to stress, protein processing in endoplasmic reticulum (ER). Moreover, the interactome and functional network analysis identified HP and HSP90AA1 as the potential glycoprotein biomarkers. These results provide unique insights into a deep understanding of the mechanisms of PFOS induced hepatotoxicity and liver disease. Our platform of multilayered glycoproteomics can be adapted to diverse ecotoxicological research.
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http://dx.doi.org/10.1016/j.envpol.2020.115774DOI Listing
January 2021

A novel binary matrix consisting of graphene oxide and caffeic acid for the analysis of scutellarin and its metabolites in mouse kidney by MALDI imaging.

Analyst 2021 Jan;146(1):289-295

Department of Chemistry and State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Kowloon Tong, Kowloon, Hong Kong SAR, P. R. China.

Although the in vivo metabolic pathways of scutellarin, a traditional Chinese medicine, have been investigated via different liquid chromatography techniques, studies on the distribution and location of scutellarin within organ tissue sections have not been reported. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) can generate in situ spatial distribution profiles for scutellarin and its metabolites in a kidney section. However, the direct detection of a small molecule (m/z < 600) using conventional matrices often results in ion suppression and matrix interferences. In this study, we demonstrated a novel methodology using MALDI-MSI for the in situ spatial localization of scutellarin and its metabolites in kidney tissues by applying a binary matrix of graphene oxide (GO) and caffeic acid (CA). The results indicated that the binary matrix (GO/CA) significantly improved the detection efficiency of scutellarin and its metabolites with relatively high sensitivity, selectivity and reproducibility on tissue sections. This methodology was successfully applied to map scutellarin and its metabolites with MALDI-MSI in mouse kidney tissues. Specifically, scutellarin and scutellarein were found to be located in the cortex and medulla regions of the kidney with relatively high abundance, whereas the remaining metabolites appeared in the cortex with low abundance. We believe that the novel imaging methodology may also be used for the studies of cancerous tissues and inform the development of the future therapies of kidney tumors.
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http://dx.doi.org/10.1039/d0an01539cDOI Listing
January 2021

Mass spectrometry-based metabolomics investigation on two different indica rice grains (Oryza sativa L.) under cadmium stress.

Food Chem 2021 May 26;343:128472. Epub 2020 Oct 26.

State key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong, China. Electronic address:

Cadmium is a toxic environmental pollutant that is readily absorbed by rice grains and poses serious threats to human health. The selection and breeding of rice varieties with low cadmium accumulation is one of the most economical and ecological methods to reduce cadmium exposure. In this study, two different indica rice grains under cadmium stress were subjected to mass spectrometry-based metabolomics analysis for the first time. When the cadmium concentration increased in rice grains, most carbohydrates and amino acids were down-regulated, except myoinositol that can prevent cadmium toxicity, which was up-regulated. d-Mannitol and l-cysteine were up-regulated with the increase of cadmium concentration in low-cadmium-accumulating rice. Also, organic acids were activated especially 13-(S)-hydroperoxy-9(Z),11(E),15(Z)-octadecatrienoicacid that is related to the alpha-linolenic acid metabolism and jasmonic acid production. The determination of biomarkers and characterization of metabolic pathways might be helpful for the selection of rice varieties with low cadmium accumulation.
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http://dx.doi.org/10.1016/j.foodchem.2020.128472DOI Listing
May 2021