Publications by authors named "Yunda Li"

6 Publications

  • Page 1 of 1

Highly Sensitive Fluorescence Detection of Global 5-Hydroxymethylcytosine from Nanogram Input with Strongly Emitting Copper Nanotags.

Anal Chem 2021 Oct 12. Epub 2021 Oct 12.

School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China.

Quantitative analysis of 5-hydroxymethylcytosine (5hmC) has remarkable clinical significance to early cancer diagnosis; however, it is limited by the requirement in current assays for large amounts of starting material and expensive instruments requring expertise. Herein, we present a highly sensitive fluorescence method, termed hmC-TACN, for global 5hmC quantification from several nanogram inputs based on terminal deoxynucleotide transferase (TdT)-assisted formation of fluorescent copper (Cu) nanotags. In this method, 5hmC is labeled with click tags by T4 phage β-glucosyltransferase (β-GT) and cross-linked with a random DNA primer via click chemistry. TdT initiates the template-free extension along the primer at the modified 5hmC site and then generates a long polythymine (T) tail, which can template the production of strongly emitting Cu nanoparticles (CuNPs). Consequently, an intensely fluorescent tag containing numerous CuNPs can be labeled onto the 5hmC site, providing the sensitive quantification of 5hmC with a limit of detection (LOD) as low as 0.021% of total nucleotides (/ = 3). With only a 5 ng input (∼1000 cells) of genomic DNA, global 5hmC levels were accurately determined in mouse tissues, human cell lines (including normal and cancer cells of breast, lung, and liver), and urines of a bladder cancer patient and healthy control. Moreover, as few as 100 cells can also be distinguished between normal and cancer cells. The hmC-TACN method has great promise of being cost effective and easily mastered, with low-input clinical utility, and even for the microzone analysis of tumor models.
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http://dx.doi.org/10.1021/acs.analchem.1c03266DOI Listing
October 2021

Pearl Necklacelike Strategy Enables Quantification of Global 5-Hydroxymethylcytosine and 5-Formylcytosine by Inductively Coupled Plasma-Atomic Emission Spectrometry.

Anal Chem 2021 06 26;93(22):7787-7791. Epub 2021 May 26.

School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China.

5-Hydroxymethylcytosine (5hmC) and 5-formylcytosine (5fC) are key intermediates of active DNA demethylation, for which the global detection methods are still restricted by high cost and long operation time. Here, we demonstrate a pearl necklacelike strategy to accurately quantify global 5hmC and 5fC in genomic DNA. In this method, the metal-organic framework (MOF), [Cu(BTC)] (denoted as HKUST-1, HBTC = 1,3,5-benzenetricarboxylic acid), with a diameter of ∼30 nm that contains ∼15 000 copper ions (Cu) as the "super label" was grown in the carboxylated 5hmC and 5fC loci of genomic DNA via the coordination between Cu and the carboxyl group. After the acid digestion of MOF, the concentration of Cu, which has a quantitative relationship with the 5hmC/5fC content, was measured by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The metal element enrichment during MOF growth has amplified the signal by 4 orders of magnitude, realizing sensitive and accurate quantification of global 5hmC and 5fC in different tissues with a detection limit of 0.031% and 0.019‰ in DNA, respectively. The bisulfite- and mass spectrometry-free strategy is easily performed in almost all research and medical laboratories and would provide potential capability to quantify other candidate modifications in nucleotides.
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http://dx.doi.org/10.1021/acs.analchem.1c01548DOI Listing
June 2021

Association between the pattern of mobile phone use and sleep quality in Northeast China college students.

Sleep Breath 2021 Feb 2. Epub 2021 Feb 2.

School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang, 110122, Liaoning, China.

Objectives: Currently, mobile penetration is high amongst college students. The aims of this study were to investigate the characteristics of mobile phone use and to explore the influence of mobile phone use characteristics on sleep quality amongst college students.

Methods: From December 2016 to January 2017, we collected mobile phone use characteristics and sleep quality data using the Pittsburgh Sleep Quality Index (PSQI) and standardised questionnaires that were answered by 4500 medical university students in Liaoning Province (actual response rate of 94%, n = 4234 college students). This study used the SPSS 21.0 software to establish the database and perform the statistical analysis.

Results: One hundred percent of the college students had mobile phones and used mobile phones for entertainment (91%), work (51%), obtaining information (61%), and other purposes (23%). Additionally, there was a statistically significant difference in the PSQI score between students who held the phone at a distance of more than 10 cm from their eyes and those who held it a distance of less than 10 cm (P = 0.002). Multiple logistic regression analysis showed that the risk of poor sleep quality was 1.21-1.53 times higher for those who spent more than 5 h a day using their phones and 1.41-1.59 times higher for those who used their phones for more than half an hour before going to bed when the lights were off.

Conclusions: Daily cumulative mobile phone use and use with the lights off before sleep are associated with poorer sleep quality.
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http://dx.doi.org/10.1007/s11325-021-02295-2DOI Listing
February 2021

Acacetin exerts antioxidant potential against atherosclerosis through Nrf2 pathway in apoE Mice.

J Cell Mol Med 2021 01 26;25(1):521-534. Epub 2020 Nov 26.

Xiamen Cardiovascular Hospital, Xiamen University, Xiamen, China.

Oxidative stress has a considerable influence on endothelial cell dysfunction and atherosclerosis. Acacetin, an anti-inflammatory and antiarrhythmic, is frequently used in the treatment of myocarditis, albeit its role in managing atherosclerosis is currently unclear. Thus, we evaluated the regulatory effects of acacetin in maintaining endothelial cell function and further investigated whether the flavonoid could attenuate atherosclerosis in apolipoprotein E deficiency (apoE ) mice. Different concentrations of acacetin were tested on EA.hy926 cells, either induced or non-induced by human oxidized low-density lipoprotein (oxLDL), to clarify its influence on cell viability, cellular reactive oxidative stress (ROS) level, apoptotic ratios and other regulatory effects. In vivo, apoE mice were fed either a Western diet or a chow diet. Acacetin pro-drug (15 mg/kg) was injected subcutaneously two times a day for 12 weeks. The effects of acacetin on the atherosclerotic process, plasma inflammatory factors and lipid metabolism were also investigated. Acacetin significantly increased EA.hy926 cell viability by reducing the ratios of apoptotic and necrotic cells at 3 μmol/L. Moreover, 3 μmol/L acacetin clearly decreased ROS levels and enhanced reductase protein expression through MsrA and Nrf2 pathway through phosphorylation of Nrf2 and degradation of Keap1. In vivo, acacetin treatment remarkably attenuated atherosclerosis by increasing reductase levels in circulation and aortic roots, decreasing plasma inflammatory factor levels as well as accelerating lipid metabolism in Western diet-fed apoE mice. Our findings demonstrate the anti-oxidative and anti-atherosclerotic effects of acacetin, in turn suggesting its potential therapeutic value in atherosclerotic-related cardiovascular diseases (CVD).
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http://dx.doi.org/10.1111/jcmm.16106DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7810944PMC
January 2021

Predictions of the dysregulated competing endogenous RNA signature involved in the progression of human lung adenocarcinoma.

Cancer Biomark 2020 ;29(3):399-416

Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, China.

Background: Lung adenocarcinoma (LUAD) is the most common histological subtype of lung cancer worldwide. Until now, the molecular mechanisms underlying LUAD progression have not been fully explained. This study aimed to construct a competing endogenous RNA (ceRNA) network to predict the progression in LUAD.

Methods: Differentially expressed lncRNAs (DELs), miRNAs (DEMs), and mRNAs (DEGs) were identified from The Cancer Genome Atlas (TCGA) database with a |log2FC|> 1.0 and a false discovery rate (FDR) < 0.05. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), protein-protein interaction (PPI) network, and survival analyses were performed to analyse these DEGs involved in the ceRNA network. Subsequently, the drug-gene interaction database (DGIdb) was utilized to select candidate LUAD drugs interacting with significant DEGs. Then, lasso-penalized Cox regression and multivariate Cox regression models were used to construct the risk score system. Finally, based on the correlations between DELs and DEGs involved in the risk score system, the final ceRNA network was identified. Meanwhile, the GEPIA2 database and immunohistochemical (IHC) results were utilized to validate the expression levels of selected DEGs.

Results: A total of 340 DELs, 29 DEMs, and 218 DEGs were selected to construct the initial ceRNA network. Functional enrichment analyses indicated that 218 DEGs were associated with the KEGG pathway terms "microRNAs in cancer", "pathways in cancer", "cell cycle", "HTLV-1 infection", and the "PI3K-Akt signalling pathway". K-M survival analysis of all differentially expressed genes involved in the ceRNA network identified 24 DELs, 4 DEMs, and 29 DEGs, all of which were significantly correlated with LUAD progression (P< 0.05). Furthermore, 15 LUAD drugs interacting with 29 significant DEGs were selected. After lasso-penalized Cox regression and multivariate Cox regression modelling, PRKCE, DLC1, LATS2, and DPY19L1 were incorporated into the risk score system, and the results suggested that LUAD patients who had the high-risk score always suffered from a poorer overall survival. Additionally, the correlation coefficients between these 4 DEGs and their corresponding DELs involved in the ceRNA network suggested that there were 2 significant DEL-DEG pairs, NAV2-AS2 - PRKCE (r= 0.430, P< 0.001) and NAV2-AS2 - LATS2 (r= 0.338, P< 0.001). And NAV2-AS2 - mir-31 - PRKCE and NAV2-SA2 - mir-31 - LATS2 were finally identified as ceRNA network involved in the progression of LUAD.

Conclusions: The lncRNA-miRNA-mRNA ceRNA network plays an essential role in predicting the progression of LUAD. These results may improve our understanding and provide novel mechanistic insights to explore prognosis and therapeutic drugs for LUAD patients.
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http://dx.doi.org/10.3233/CBM-200133DOI Listing
July 2021

[Rapid determination of 12 semi-volatile pesticide residues in vegetables by miniaturized thermal-assisted purge-and-trap coupled with ultra high pressure liquid chromatography-tandem mass spectrometry].

Se Pu 2020 Jan;38(1):120-126

School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China.

A method for the analysis of 12 semi-volatile pesticide residues in vegetables was developed by miniaturized thermal-assisted purge-and-trap coupled with ultra high pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Under the optimized conditions, the sample preparation could be completed within 10 min. The linear relationships of the 12 semi-volatile pesticide residues were good within their corresponding concentration ranges. The correlation coefficients were in range of 0.9918-0.9997. The limits of detection and limits of quantification were in range of 0.3-1.3 μg/kg and 1.0-4.3 μg/kg, respectively. The recoveries ranged from 80.0% to 120.0%, with intra-day and inter-day RSDs of less than 10%. This proposed method is quick and simple, and is suitable for the simultaneous and rapid analysis of semi-volatile pesticide residues in vegetables.
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http://dx.doi.org/10.3724/SP.J.1123.2019.01051DOI Listing
January 2020
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