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1.
Nat Commun ; 14(1): 1246, 2023 Mar 04.
Article in English | MEDLINE | ID: mdl-36870994

ABSTRACT

The adoption of electric vehicles (EVs) on a large scale is crucial for meeting the desired climate commitments, where affordability plays a vital role. However, the expected surge in prices of lithium, cobalt, nickel, and manganese, four critical materials in EV batteries, could hinder EV uptake. To explore these impacts in the context of China, the world's largest EV market, we expand and enrich an integrated assessment model. We find that under a high material cost surge scenario, EVs would account for 35% (2030) and 51% (2060) of the total number of vehicles in China, significantly lower than 49% (2030) and 67% (2060) share in the base-line, leading to a 28% increase in cumulative carbon emissions (2020-2060) from road transportation. While material recycling and technical battery innovation are effective long-term countermeasures, securing the supply chains of critical materials through international cooperation is highly recommended, given geopolitical and environmental fragilities.

2.
Sensors (Basel) ; 22(18)2022 Sep 12.
Article in English | MEDLINE | ID: mdl-36146231

ABSTRACT

Maneuvering target imaging based on inverse synthetic aperture radar (ISAR) imaging has recently drawn significant attention. Among the many autofocusing technologies which are crucial in ISAR imaging, minimum-entropy-based autofocusing (MEA) is highly robust. However, traditional MEA is not suitable for terahertz (THz) ISAR imaging. For one thing, the iterative process in traditional MEA is too complicated to be utilized for THz-ISAR imaging with tremendous data. For another, THz wavelengths are very short and extremely sensitive to phase errors, so the compensation accuracy of the traditional MEA method can hardly meet the requirements of THz radar high-resolution imaging. Therefore, in this paper, the MEA algorithm based on the damped Newton method is proposed, which improves computational efficiency by approximating the first- and second-order partial derivatives of the image entropy function with respect to the phase errors, as well as by the fast Fourier transform (FFT). The search step size factor is introduced to ensure that the algorithm can converge along the declination direction of the entropy function and obtain the globally optimal ISAR image. The experimental results validated the efficiency of the proposed algorithm, which is promising in THz-ISAR imaging of maneuvering targets.

3.
Int J Mol Sci ; 23(10)2022 May 23.
Article in English | MEDLINE | ID: mdl-35628638

ABSTRACT

Polylactic acid-glycolic acid (PLGA) has been widely used in bone tissue engineering due to its favorable biocompatibility and adjustable biodegradation. 3D printing technology can prepare scaffolds with rich structure and function, and is one of the best methods to obtain scaffolds for bone tissue repair. This review systematically summarizes the research progress of 3D-printed, PLGA-based scaffolds. The properties of the modified components of scaffolds are introduced in detail. The influence of structure and printing method change in printing process is analyzed. The advantages and disadvantages of their applications are illustrated by several examples. Finally, we briefly discuss the limitations and future development direction of current 3D-printed, PLGA-based materials for bone tissue repair.


Subject(s)
Tissue Engineering , Tissue Scaffolds , Bone and Bones , Glycolates , Polyesters , Printing, Three-Dimensional , Tissue Engineering/methods , Tissue Scaffolds/chemistry
4.
Appl Opt ; 61(35): 10390-10399, 2022 Dec 10.
Article in English | MEDLINE | ID: mdl-36607097

ABSTRACT

The intelligent reflecting surface (IRS) and angle diversity receiver (ADR) jointly assisted indoor visible light communication (VLC) system is proposed to improve average signal-to-noise ratio (ASNR) performance. Specifically, to maximize the ASNR at the receiving plane, the roll angle and yaw angle of IRS and the inclination angle of the side detector in the ADR structure are optimized simultaneously as one non-convex problem. With the bat algorithm, the optimal solution is numerically obtained. Results show that when the transmit power of the light emitting diode lamp array is 1 W, the ASNRs of this VLC system optimized by IRS and ADR are approximately 7.89 dB, 3.58 dB, and 2.09 dB higher than those of the original, IRS-assisted, and ADR-assisted VLC systems, respectively. Furthermore, the transmission rate and bit error rate performances of the original, IRS-assisted, ADR-assisted, and IRS and ADR jointly assisted indoor VLC systems are also simulated and compared; it is found that the performance improvement of the indoor VLC system jointly optimized by IRS and ADR is more evident than that of the other three VLC systems. This study will benefit the research and development of indoor VLC systems.

5.
Pathol Oncol Res ; 28: 1610751, 2022.
Article in English | MEDLINE | ID: mdl-36590386

ABSTRACT

About 70% of non-small cell lung cancer (NSCLC) patients require radiotherapy. However, due to the difference in radiation sensitivity, the treatment outcome may differ for the same pathology and choice of treatment. Poly (ADP-ribose) polymerase 1 (PARP-1) is a key gene responsible for DNA repair and is involved in base excision repair as well as repair of single strand break induced by ionizing radiation and oxidative damage. In order to investigate the relationship between PARP-1 gene polymorphism and radiation sensitivity in NSCLC, we collected 141 primary NSCLC patients undergoing three-dimensional conformal radiotherapy. For each case, the gross tumor volumes (GTV) before radiation and that after 40 Gy radiation were measured to calculate the tumor regression rate. TaqMan real-time polymerase chain reaction was performed to genotype the single-nucleotide polymorphisms (SNPs). Genotype frequencies for PARP-1 genotypes were 14.2% for C/C, 44.7% for C/G and 41.1% for G/G. The average tumor regression rate after 40 Gy radiation therapy was 35.1% ± 0.192. Tumor regression rate of mid-term RT of C/C genotype was 44.6% ± 0.170, which was higher than that of genotype C/G and G/G (32.4% ± 0.196 and 34.8% ± 0.188, respectively) with statistical significance (F = 3.169 p = 0.045). The higher tumor regression rate in patients with C/C genotype suggested that G allele was a protective factor against radiation therapy. Using the median tumor regression rate of 34%, we divided the entire cohort into two groups, and found that the frequency distribution of PARP-1 gene rs3219073 had significant difference between these two groups (p < 0.05). These results showed that PARP-1 gene polymorphism may affect patient radiation sensitivity and predict the efficacy of radiotherapy. It therefore presents an opportunity for developing new therapeutic targets to improve radiotherapy outcome.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Radiation Tolerance , Humans , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/radiotherapy , Carcinoma, Non-Small-Cell Lung/drug therapy , DNA Repair/genetics , Lung Neoplasms/genetics , Lung Neoplasms/radiotherapy , Lung Neoplasms/drug therapy , Polymorphism, Single Nucleotide/genetics , Radiation Tolerance/genetics
6.
RSC Adv ; 11(29): 17683-17693, 2021 May 13.
Article in English | MEDLINE | ID: mdl-35480180

ABSTRACT

Polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and polychlorinated dibenzothiophenes/thianthrenes (PCDT/TAs) are two groups of dioxin-like compounds with oxygen and sulfur substitution, respectively. Chlorophenols (CPs) and chlorothiophenols (CTPs) are direct precursors in PCDD/F and PCDT/TA formation. The formation of chlorophenoxy radicals (CPRs) and chlorothiophenoxy radicals (CTPRs) from chlorophenols (CPs) and chlorothiophenols (CTPs) with O(3P) is an important initial step for the formation of PCDD/Fs and PCDT/TAs, respectively. In this paper, the formation of CPRs/CTPRs from the complete series reactions of 19 CP/CTP congeners with O(3P) was studied using the density functional theory (DFT) method. The rate constants of each reaction were calculated using canonical variational transition state (CVT) theory along with a small-curvature tunneling (SCT) contribution over a wide temperature range of 600-1200 K. The effect of the chlorine substitution pattern on the structural parameters, thermochemical properties and rate constants in both CPs and CTPs was discussed. This study shows that the reactions between CPs and O(3P) can be affected by the chlorine substitution at the para-position, and the reactions between CTPs and O(3P) are mostly influenced by both ortho-substitutions. The thiophenoxyl-hydrogen abstraction from CTPs by O(3P) is more likely to occur than the phenoxyl-hydrogen abstraction from CPs by O(3P). Comparison of the reactivity of CP/CTPs with O(3P) with our previous work on CP/CTPs with H and OH shows that the order for phenoxyl-hydrogen abstraction potential is CP + OH > CP + O(3P) > CP + H, and the order for thiophenoxyl-hydrogen abstraction potential is CTP + O(3P) > CTP + H > CTP + OH.

7.
J Environ Sci (China) ; 100: 328-339, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33279046

ABSTRACT

Amides, a series of significant atmospheric nitrogen-containing volatile organic compounds (VOCs), can participate in new particle formation (NPF) throught interacting with sulfuric acid (SA) and organic acids. In this study, we investigated the molecular interactions of formamide (FA), acetamide (AA), N-methylformamide (MF), propanamide (PA), N-methylacetamide (MA), and N,N-dimethylformamide (DMF) with SA, acetic acid (HAC), propanoic acid (PAC), oxalic acid (OA), and malonic acid (MOA). Global minimum of clusters were obtained through the association of the artificial bee colony (ABC) algorithm and density functional theory (DFT) calculations. The conformational analysis, thermochemical analysis, frequency analysis, and topological analysis were conducted to determine the interactions of hydrogen-bonded molecular clusters. The heterodimers formed a hepta or octa membered ring through four different types of hydrogen bonds, and the strength of the bonds are ranked in the following order: SOH•••O > COH•••O > NH•••O > CH•••O. We also evaluated the stability of the clusters and found that the stabilization effect of amides with SA is weaker than that of amines with SA but stronger than that of ammonia (NH3) with SA in the dimer formation of nucleation process. Additionally, the nucleation capacity of SA with amides is greater than that of organic acids with amides.


Subject(s)
Amides , Hydrogen , Hydrogen Bonding , Models, Theoretical , Sulfuric Acids
8.
Food Chem Toxicol ; 147: 111901, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33279676

ABSTRACT

Functional components including ß-glucan, dietary fiber, resistant starch and polyphenols extracted from various coarse cereals have been reported to prevent high-fat diet (HFD) induced obesity via modulating gut microbiota. In this study, millet, maize, oat, soybean, and purple potato were ultrafine comminuted, mixed, and then extruded for the preparation of puffed mixture coarse cereals. HFD was used to investigate the effects of mixture coarse cereals on obesity and gut microbiota in mice. The results showed that dietary intake of mixture coarse cereals could decrease body weight gain and fat accumulation, improve the blood glucose tolerance and serum lipids levels, reduce the systemic inflammation, and down-regulate the expression of hepatic lipogenic genes. In addition, the levels of SCFAs and the composition of gut microbiota were investigated. The results indicated that mixture coarse cereals could promote the release of SCFAs, enhance the diversity of gut microbiota, and increase the relative abundance of Lactobacillus and Bifidobacterium, which might contribute to the anti-obesity activity. Present work suggested that the mixture coarse cereals could be developed as a nutraceutical for the prevention of HFD-induced obesity.


Subject(s)
Cytokines/metabolism , Diet, High-Fat/adverse effects , Edible Grain , Gastrointestinal Microbiome/drug effects , Obesity/chemically induced , Obesity/prevention & control , Animal Feed/analysis , Animals , Bacteria/genetics , Blood Glucose , Cytokines/genetics , DNA, Bacterial/genetics , Dietary Fiber , Fatty Acids, Volatile , Feces/microbiology , Inflammation , Male , Mice , Mice, Inbred C57BL
9.
Sci Total Environ ; 723: 137987, 2020 Jun 25.
Article in English | MEDLINE | ID: mdl-32224394

ABSTRACT

Aerosol samples from all over the word contained 2-methyltetrol sulfate ester (MTS). We investigated the role of MTS in new particle formation (NPF) with aerosol nucleation precursors, including sulfuric acid (SA), water (W), ammonia (N), methylamine (MA), dimethylamine (DMA), and trimethylamine (TMA). The analysis was performed using quantum chemical approach, kinetic calculation and molecular dynamics (MD) simulations. The results proved that the molecular interactions in the clusters were mainly H-bonds and electrostatic interaction. The negative Gibbs free energy changes for all the studied MTS-containing clusters indicated that the formation of these clusters was thermodynamically favorable. The stability of the clusters was evaluated according to the total evaporation rate. Here, (MTS)(SA) and (MTS)(W) were the most and least stable cluster, respectively. MD simulations were used for time and spatial analysis of the role of the MTS-SA system. The results indicated that MTS can self-aggregate or absorb SA molecules into clusters, larger than the size of the critical cluster (approximately 1 nm), suggesting that MTS can initiate NPF by itself or together with SA.

10.
J Agric Food Chem ; 68(7): 1974-1985, 2020 Feb 19.
Article in English | MEDLINE | ID: mdl-31971785

ABSTRACT

Our aim was to investigate DNA mismatch repair (MMR) genes regulating cadmium tolerance in two soybean cultivars. Cultivars Liaodou 10 (LD10, Cd-sensitive) and Shennong 20 (SN20, Cd-tolerant) seedlings were grown hydroponically on Murashige and Skoog (MS) media containing 0-2.5 mg·L-1 Cd for 4 days. Cd stress induced less random amplified polymorphism DNA (RAPD) polymorphism in LD10 than in SN20 roots, causing G1/S arrest in LD10 and G2/M arrest in SN20 roots. Virus-induced gene silencing (VIGS) of MLH1 in LD10-TRV-MLH1 plantlets showed markedly diminished G1/S arrest but enhanced root length/area under Cd stress. However, an increase in G1/S arrest and reduction of G2/M arrest occurred in SN20-TRV-MSH2 and SN20-TRV-MSH6 plantlets with decreased root length/area under Cd stress. Taken together, we conclude that the low expression of MSH2 and MSH6, involved in the G2/M arrest, results in Cd-induced DNA damage recognition bypassing the MMR system to activate G1/S arrest with the assistance of MLH1. This then leads to repressed root growth in LD10, explaining the intervarietal difference in Cd tolerance in soybean.


Subject(s)
Cadmium/metabolism , DNA-Binding Proteins/metabolism , Glycine max/genetics , Glycine max/metabolism , Plant Proteins/metabolism , Cadmium/toxicity , DNA Damage/drug effects , DNA Mismatch Repair/drug effects , DNA-Binding Proteins/genetics , G2 Phase Cell Cycle Checkpoints , Plant Proteins/genetics , Glycine max/drug effects
11.
Chemosphere ; 246: 125614, 2020 May.
Article in English | MEDLINE | ID: mdl-31883478

ABSTRACT

Cadmium (Cd) is found widely in soil and is severely toxic for plants, causing oxidative damage in plant cells because of its heavy metal characteristics. The DNA damage response (DDR) is triggered in plants to cope with the Cd stress. The DNA mismatch repair (MMR) system known for its mismatch repair function determines DDR, as mispairs are easily generated by a translesional synthesis under Cd-induced genomic instability. Cd-induced mismatches are recognized by three heterodimeric complexes including MutSα (MSH2/MSH6), MutSß (MSH2/MSH3), and MutSγ (MSH2/MSH7). MutLα (MLH1/PMS1), PCNA/RFC, EXO1, DNA polymerase δ and DNA ligase participate in mismatch repair in turn. Meanwhile, ATR is preferentially activated by MSH2 to trigger DDR including the regulation of the cell cycle, endoreduplication, cell death, and recruitment of other DNA repair, which enhances plant tolerance to Cd. However, plants with deficient MutS will bypass MMR-mediated DDR and release the multiple-effect MLH1 from requisition of the MMR system, which leads to weak tolerance to Cd in plants. In this review, we systematically illustrate how the plant DNA MMR system works in a Cd-induced DDR, and how MMR genes regulate plant tolerance to Cd. Additionally, we also reviewed multiple epigenetic regulation systems acting on MMR genes under stress.


Subject(s)
Cadmium/toxicity , DNA Damage/drug effects , DNA Mismatch Repair , Plants/genetics , Epigenesis, Genetic , Humans
12.
Int J Mol Sci ; 20(11)2019 May 28.
Article in English | MEDLINE | ID: mdl-31141990

ABSTRACT

Chlorothiophenols (CTPs) are known to be key and direct precursors of polychlorinated thianthrene/dibenzothiophenes (PCTA/DTs). Self/cross-coupling of the chlorothiophenoxy radicals (CTPRs), sulfydryl-substituted phenyl radicals and thiophenoxyl diradicals evolving from CTPs are initial and important steps for PCTA/DT formation. In this study, quantum chemical calculations were carried out to investigate the homogenous gas-phase formation of PCTA/DTs from self/cross-coupling of 2,4-dichlorothiophenoxy radical (R1), 2-sulfydryl-3,5-dichlorophenyl radical (R2) and 3,5-dichlorothiophenoxyl diradical (DR) at the MPWB1K/6-311+G(3df,2p)//MPWB1K/6-31+G(d,p) level. The rate constants of crucial elementary steps were deduced over 600-1200 K, using canonical variational transition state theory with a small curvature tunneling contribution. For the formation of PCTAs, the S•/σ-C• condensation with both thiophenolic sulfur in one radical and ortho carbon in the other radical bonded to single electron is the most efficient sulfur-carbon coupling mode, and the ranking of the PCTA formation potential is DR + DR > R2 + DR > R1 + DR > R1 + R2 > R1 + R1. For the formation of PCDTs, the σ-C•/σ-C• coupling with both ortho carbon in the two radicals bonded to single electron is the energetically favored carbon-carbon coupling mode, and the ranking of the PCDT formation potential is: R2 + DR > R2 + R2 > R1 + DR > R1 + R2 > R1 + R1. The PCTA/DTs could be produced from R1, R2 and DR much more readily than PCDD/DFs from corresponding oxygen substituted radicals.


Subject(s)
Heterocyclic Compounds/chemical synthesis , Sulfhydryl Compounds/chemical synthesis , Thiophenes/chemical synthesis , Computer Simulation , Kinetics
13.
Plant Physiol Biochem ; 141: 40-50, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31128562

ABSTRACT

Agrobacterium-mediated soybean transformation has been greatly improved in recent years, however the transformation efficiency is still low and highly genotype-dependent when compared to other species. Here, we characterized seventeen soybean genotypes based on their genetic transformation efficiencies, i.e., high and low, during Agrobacterium-mediated transformation. To reveal the molecular basis of this transformation difference, we constructed a highly efficient transient transgene expression system using soybean cotyledon protoplasts and then assess the methylation levels of promoter and coding regions of an EYFP (enhanced yellow fluorescent protein) gene introduced into the protoplast cultures of various soybean genotypes using BSP (bisulfite sequencing PCR). Increased methylation was found to be associated with the considerably decreased transfection efficiency (as percentage of EYFP fluorescent protoplasts) in low-efficacy genotypes as compared with those in high-efficacy on three DAT (day after transfection). 5-Azacytidine (5-Azac), a demethylating reagent commonly applied in epigenetic researches, significantly improved the transient transfection efficiency and transgene expression level in low-efficiency genotypes. Furthermore, the shoot regeneration efficiency in low-efficiency genotypes was substantially increased by 5-Azac treatment in an Agrobacterium-mediated soybean transformation system. Taken together, we concluded that lower methylation level in transgene contributed to enhanced shoot regeneration in Agrobacterium-mediated soybean transformation.


Subject(s)
Agrobacterium tumefaciens/genetics , Azacitidine/pharmacology , Gene Transfer Techniques , Glycine max/drug effects , Plant Shoots/drug effects , Cotyledon/genetics , DNA Methylation , Fabaceae/genetics , Genes, Plant , Genotype , Methylation , Peptide Hydrolases/metabolism , Plants, Genetically Modified/genetics , Protoplasts , Regeneration , Sequence Analysis, DNA , Glycine max/genetics , Transfection , Transformation, Genetic , Transgenes
14.
Int J Mol Sci ; 20(7)2019 Mar 27.
Article in English | MEDLINE | ID: mdl-30934774

ABSTRACT

Polychlorinated phenoxathiins (PCPTs), polychlorinated dibenzothiophenes (PCDTs), and polychlorinated thianthrenes (PCTAs) are sulfur analogues of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/DFs). Chlorothiophenols (CTPs) and chlorophenols (CPs) are key precursors for the formation of PCTA/PT/DTs, which can react with H or OH to form chloro(thio)phenoxy radical, sulfydryl/hydroxyl-substituted phenyl radicals, and (thio)phenoxyl diradicals. However, previous radical/radical PCTA/DT formation mechanisms in the literature failed to explain the higher concentration of PCDTs than that of PCTAs under the pyrolysis or combustion conditions. In this work, a detailed thermodynamics and kinetic calculations were carried out to investigate the pre-intermediate formation for PCTA/PT/DTs from radical/molecule coupling of the 2-C(T)P with their key radical species. Our study showed that the radical/molecule coupling mechanism explains the gas-phase formation of PCTA/PT/DTs in both thermodynamic and kinetic perspectives. The S/C coupling modes to form thioether-(thio)enol intermediates are preferable over the O/C coupling modes to form ether-(thio)enol intermediates. Thus, although the radical/molecule coupling of chlorophenoxy radical with 2-C(T)P has no effect on the PCDD/PT formation, the radical/molecule coupling of chlorothiophenoxy radical with 2-C(T)P plays an important role in the PCTA/PT formation. Most importantly, the pre-PCDT intermediates formation pathways from the couplings of sulfydryl/hydroxyl-substituted phenyl radical with 2-C(T)P and (thio)phenoxyl diradicals with 2-C(T)P are more favorable than pre-PCTA/PT intermediates formation pathways from the coupling of chlorothiophenoxy radical with 2-C(T)P, which provides reasonable explanation for the high PCDT-to-PCTA ratio in the environment.


Subject(s)
Chlorophenols/chemistry , Dibenzofurans/chemistry , Heterocyclic Compounds/chemistry , Quantum Theory , Thiophenes/chemistry , Free Radicals/chemistry , Kinetics , Molecular Conformation
15.
RSC Adv ; 9(62): 36171-36181, 2019 Nov 04.
Article in English | MEDLINE | ID: mdl-35540604

ABSTRACT

Aromatic acids, which are generated from numerous anthropogenic emissions and secondary transformations, have been considered to play a crucial role in new particle formation. In this study, we performed theoretical calculations at the PW91PW91/6-311++G(3df,3pd) level to investigate the interaction between typical aromatic acids namely benzoic acid (BA), phenylacetic acid (PAA), phthalic acid (PA), isophthalic acid (mPA), and terephthalic acid (PTA) and common atmospheric nucleation precursors namely sulfuric acid (SA), water (H2O), ammonia (NH3), methylamine (MA), dimethylamine (DMA), and trimethylamine (TMA). The geometric analysis, Gibbs free energy analysis, OH/NH-stretching vibrational frequency calculation, and atoms in molecules (AIM) analysis were conducted to determine the interactions in the complexes. The heterodimers formed a six to eight membered ring through four types of hydrogen bond, and the bond strength could be ranked in descending order: SO-H⋯O > O-H⋯O/N > N-H⋯O. The BA/PAA/mPA/PTA-SA complexes had the lowest Gibbs free energy values. PA was more likely to interact with NH3 or amines rather than SA due to an intra-molecular hydrogen bond. Additionally, the aromatic acids have similar ability to interact with SA and NH3 as monocarboxylic/dicarboxylic acid. The formation potential of the heterodimers from aromatic acids with common nucleation precursors in ambient atmosphere was investigated.

16.
Chemosphere ; 201: 586-594, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29533809

ABSTRACT

DNA mismatch repair (MMR) proteins have been implicated in sensing and correcting DNA damage, and in governing cell cycle progression in the presence of structurally anomalous nucleotide lesions induced by different stresses in mammalian cells. Here, Arabidopsis seedlings were grown hydroponically on 0.5 × MS media containing cadmium (Cd) at 0-4.0 mg L-1 for 5 d. Flow cytometry results indicated that Cd stress induced a G2/M cell cycle arrest both in MLH1-, MSH2-, MSH6-deficient, and in WT roots, associated with marked changes of G2/M regulatory genes, including ATM, ATR, SOG1, BRCA1, WEE1, CYCD4; 1, MAD2, CDKA;1, CYCB1; 2 and CYCB1; 1. However, the Cd-induced G2/M phase arrest was markedly diminished in the MSH2- and MSH6-deficient roots, while a lack of MLH1 had no effect on Cd-induced G2 phase arrest relative to that in the wild type roots under the corresponding Cd stress. Expression of the above G2/M regulatory genes was altered in MLH1, MSH2 and MSH6-deficient roots in response to Cd treatment. Furthermore, Cd elicited endoreplication in MSH2- and MSH6-deficient roots, but not in MLH1-deficient Arabidopsis roots. Results suggest that MSH2 and MSH6 may act as direct sensors of Cd-mediated DNA damage. Taken together, we conclude that MSH2 and MSH6, but not MLH1, components of the MMR system are involved in the G2 phase arrest and endoreplication induced by Cd stress in Arabidopsis roots.


Subject(s)
Arabidopsis Proteins/genetics , Arabidopsis/drug effects , Cadmium/toxicity , Environmental Pollutants/toxicity , G2 Phase Cell Cycle Checkpoints/drug effects , MutS Homolog 2 Protein/genetics , Arabidopsis/genetics , DNA Damage/genetics , DNA Mismatch Repair/genetics , G2 Phase Cell Cycle Checkpoints/genetics , Humans , Plant Roots/drug effects , Plant Roots/genetics , Seedlings/drug effects , Seedlings/genetics
17.
J Cancer Res Ther ; 14(Supplement): S72-S78, 2018.
Article in English | MEDLINE | ID: mdl-29578153

ABSTRACT

BACKGROUND: Nonsmall cell lung cancer (NSCLC) mainly contains adenocarcinoma (AC) and squamous cell carcinoma (SqCC). This study investigated single nucleotide polymorphism (SNP) of topoisomerase II alpha (TOP2A) and dual-specificity phosphatase 6 (DUSP6) in a hospital-based case and control cohort of individuals for association with risk of different histological subtypes of NSCLC. MATERIALS AND METHODS: A total of 454 (237 SqCC and 217 AC) NSCLC patients, and 454 healthy controls were recruited for analysis of TOP2A rs471692 and DUSP6 rs2279574 genotypes using the TaqMan polymerase chain reaction technique. RESULTS: TOP2A rs471692 and DUSP6 rs2279574 SNPs were in complete linkage disequilibrium; however, frequency of DUSP6 rs2279574 genotype was significantly different between the case and control, that is, DUSP6 rs2279574a/A and A/C genotypes might contribute to an increased risk of lung squamous carcinoma compared with the C/C genotype. Moreover, DUSP6 rs2279574 AA genotype was also significantly associated with advanced stages of lung cancer. In contrast, frequency of the TOP2A rs471692 genotype had no association between cases and controls (P = 0.906). Genotype frequency of DUSP6 rs2279574 was 11.9% for C/C, 43.6% for C/A, and 44.5% for A/A in the case versus 16.7% C/C, 43.4% C/A, and 39.9% A/A in the control population (χ2 = 3.136, P= 0.077 by Hardy-Weinberg equilibrium test [HWE]). The genotype frequency of TOP2A rs471692 was 50.0% for C/C, 41.6% for C/T, and 8.4% for T/T in the case versus 50.2% C/C, 43.0% C/T, and 6.8% T/T in the control populations (χ2 = 0.023, P= 0.879 by HWE test). CONCLUSION: Individuals are carrying DUSP6 rs2279574 AA and AC genotypes associated with an increased risk in developing lung squamous carcinoma in Han Chinese and with advanced NSCLC stages.


Subject(s)
Carcinoma, Squamous Cell/epidemiology , Carcinoma, Squamous Cell/genetics , Dual Specificity Phosphatase 6/genetics , Genetic Predisposition to Disease , Genetic Variation , Lung Neoplasms/epidemiology , Lung Neoplasms/genetics , Alleles , Asian People/genetics , Case-Control Studies , China/epidemiology , DNA Topoisomerases, Type II/genetics , Female , Gene Frequency , Genetic Association Studies , Genotype , Humans , Linkage Disequilibrium , Male , Neoplasm Staging , Poly-ADP-Ribose Binding Proteins/genetics , Polymorphism, Single Nucleotide , Risk Assessment , Risk Factors
18.
Ecotoxicol Environ Saf ; 145: 569-574, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28800532

ABSTRACT

Accumulating evidence demonstrates that the aberrant expression of cell cycle regulation and DNA repair genes can result in abnormal cell proliferation and genomic instability in eukaryotic cells under different stresses. Herein, Arabidopsis thaliana (Arabidopsis) seedlings were grown hydroponically on 0.5 × MS media containing cadmium (Cd) at 0-2.5mgL-1 for 5d of treatment. Real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis revealed that expression of DNA damage repair and cell cycle regulation genes, including BRCA1, MRE11, WEE1, CDKA;1 and PCNA1, showed an inverted U-shaped dose-response. In contrast, notably reduced expression was observed for G1-to-S transition-related genes, Histone H4, E2Fa and PCNA2; DSB end processing, GR1; G2-to-M transition-related gene, CYCB1;1; and DNA mismatch repair, MSH2, MSH6 and MLH1 genes in root tips exposed to 0.125-2.5mg/L Cd for 5d. Flow cytometry (FCM) analysis revealed significant increases of cells with a 2C nuclear content and with a 4C and 8C nuclear content under Cd stresses of 0.125 and 1-2.5mgL-1, respectively. Our results suggest that 0.125mgL-1 Cd-induced DNA damage induced the marked G1/S arrest, leading to accelerated growth in root tips, while 1.0-2.5mgL-1 Cd-induced DNA damage caused a notable G2/M arrest in root tips, leading to reduced growth in root tips. This may be a protective mechanism that prevents cells with damaged DNA from dividing under Cd stress.


Subject(s)
Arabidopsis/drug effects , Cadmium/toxicity , Cell Cycle Checkpoints/drug effects , DNA Damage , Meristem/drug effects , Soil Pollutants/toxicity , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Cell Cycle Checkpoints/genetics , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Genomic Instability/drug effects , Meristem/genetics , Seedlings/drug effects , Seedlings/genetics
19.
Sci Rep ; 7: 44256, 2017 03 09.
Article in English | MEDLINE | ID: mdl-28276511

ABSTRACT

PM2.5 is the main particulate air pollutant whose aerodynamic diameter is less than 2.5 micron. The inflammation of various respiratory diseases are associated with PM2.5 inhalation. Pro-inflammatory cytokine IL-1ß generated from effected cells usually plays a crucial role in many kinds of lung inflammatory reactions. The exacerbation of Th immune responses are identified in some PM2.5 related diseases. To elucidate the underlying mechanism of PM2.5-induced acute lung inflammation, we exposed Balb/c mice to PM2.5 intratracheally and established a mice model. Acute lung inflammation and increased IL-1ß expression was observed after PM2.5 instillation. Regulatory factors of IL-1ß (TLR4/MyD88 signaling pathway and NLRP3 inflammasome) participated in this lung inflammatory response as well. Treatment with compound essential oils (CEOs) substantially attenuated PM2.5-induced acute lung inflammation. The decreased IL-1ß and Th immune responses after CEOs treatment were significant. PM2.5 may increase the secretion of IL-1ß through TLR4/MyD88 and NLRP3 pathway resulting in murine airway inflammation. CEOs could attenuate the lung inflammation by reducing IL-1ß and Th immune responses in this model. This study describes a potentially important mechanism of PM2.5-induced acute lung inflammation and that may bring about novel therapies for the inflammatory diseases associated with PM2.5 inhalation.


Subject(s)
Air Pollutants/toxicity , Oils, Volatile/pharmacology , Particulate Matter/toxicity , Pneumonia/prevention & control , Acute Disease , Air Pollutants/chemistry , Animals , Gene Expression/drug effects , Gene Expression/immunology , Inflammasomes/drug effects , Inflammasomes/metabolism , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Lung/drug effects , Lung/immunology , Lung/metabolism , Mice, Inbred BALB C , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Particle Size , Particulate Matter/chemistry , Pneumonia/etiology , Pneumonia/metabolism , Signal Transduction/drug effects , Signal Transduction/genetics
20.
Med Sci Monit ; 23: 984-993, 2017 Feb 23.
Article in English | MEDLINE | ID: mdl-28231233

ABSTRACT

BACKGROUND Mutations of DNA topoisomerase II (TOP2A) are associated with chemotherapy resistance, whereas dual-specificity phosphatase 6 (DUSP6) negatively regulates members of the mitogen-activated protein (MAP) kinase superfamily to control cell proliferation. This study assessed TOP2A and DUSP6 single nucleotide polymorphisms (SNPs) in non-small cell lung cancer (NSCLC) patients for association with chemoradiotherapy responses and prognosis. MATERIAL AND METHODS A total of 140 Chinese patients with histologically confirmed NSCLC were enrolled and subjected to genotyping of TOP2A rs471692 and DUSP6 rs2279574 using Taqman PCR. An independent sample t test was used to analyze differences in tumor regression after radiotherapy versus SNP risk factors. Kaplan-Meier curves analyzed overall survival, followed by the log-rank test and Cox proportional hazard models. RESULTS There were no significant associations of TOP2A rs471692 and DUSP6 rs2279574 polymorphisms or clinicopathological variables with response to chemoradiotherapy (p>0.05). Comparing overall survival of 87 patients with stage I-III NSCLC treated with radiotherapy or chemoradiotherapy to clinicopathological variables, the data showed that tumor regression, weight loss, clinical stage, and cigarette smoking were independent prognostic predictors (p=0.009, 0.043, 0.004, and 0.025, respectively). Tumor regression rate >0.34 was associated with patent survival versus tumor regression rate ≤0.34 (p=0.007). CONCLUSIONS TOP2A rs471692 and DUSP6 rs2279574 SNPs were not associated with chemoradiotherapy response, whereas tumor regression, weight loss, clinical stage, and cigarette smoking were independent prognostic predictors for these Chinese patients with NSCLC.


Subject(s)
Antigens, Neoplasm/genetics , Carcinoma, Non-Small-Cell Lung/enzymology , Carcinoma, Non-Small-Cell Lung/radiotherapy , DNA Topoisomerases, Type II/genetics , DNA-Binding Proteins/genetics , Dual Specificity Phosphatase 6/genetics , Lung Neoplasms/enzymology , Lung Neoplasms/radiotherapy , Adult , Aged , Aged, 80 and over , Antigens, Neoplasm/metabolism , Asian People/genetics , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/pathology , Chemoradiotherapy , China , DNA Topoisomerases, Type II/metabolism , DNA-Binding Proteins/metabolism , Dual Specificity Phosphatase 6/metabolism , Ethnicity/genetics , Female , Humans , Lung Neoplasms/genetics , Male , Middle Aged , Mutation , Polymorphism, Single Nucleotide , Prognosis , Treatment Outcome
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