RVE2, a new regulatory factor in jasmonic acid pathway, orchestrates resistance to Verticillium wilt.

Verticillium dahliae, one of the most destructive fungal pathogens of several crops, challenges the sustainability of cotton productivity worldwide because very few widely-cultivated Upland cotton varieties are resistant to Verticillium wilt (VW). Here, we report that REVEILLE2 (RVE2), the Myb-like transcription factor, confers the novel function in resistance to VW by regulating the jasmonic acid (JA) pathway in cotton. RVE2 expression was essentially required for the activation of JA-mediated disease-resistance response. RVE2 physically interacted with TPL/TPRs and disturbed JAZ proteins to recruit TPL and TPR1 in NINJA-dependent manner, which regulated JA response by relieving inhibited-MYC2 activity. The MYC2 then bound to RVE2 promoter for the activation of its transcription, forming feedback loop. Interestingly, a unique truncated RVE2 widely existing in D-subgenome (GhRVE2D) of natural Upland cotton represses the ability of the MYC2 to activate GhRVE2A promoter but not GausRVE2 or GbRVE2. The result could partially explain why Gossypium barbadense popularly shows higher resistance than Gossypium hirsutum. Furthermore, disturbing the JA-signalling pathway resulted into the loss of RVE2-mediated disease-resistance in various plants (Arabidopsis, tobacco and cotton). RVE2 overexpression significantly enhanced the resistance to VW. Collectively, we conclude that RVE2, a new regulatory factor, plays a pivotal role in fine-tuning JA-signalling, which would improve our understanding the mechanisms underlying the resistance to VW.

Hsa-miR-195-5p Inhibits Autophagy and Gemcitabine Resistance of Lung Adenocarcinoma Cells via E2F7/CEP55.

Lung adenocarcinoma (LUAD) is a common malignancy. Many studies have shown that LUAD is resistant to gemcitabine chemotherapy, resulting in poor treatment outcomes in patients. We designed this study to reveal influences of hsa-miR-195-5p/E2F7/CEP55 axis on gemcitabine resistance and autophagy of LUAD cells. The expression data of LUAD-related mRNAs were downloaded from TCGA-LUAD database for differential expression analysis. The bioinformatics databases (hTFtarget, starBase and TargetScan) were used to predict the upstream and downstream regulatory molecules of E2F7. Then the binding relationships between E2F7 and regulatory molecules were verified by ChIP and dual-luciferase reporter assay. qRT-PCR and western blot were used to detect the mRNA and protein levels of has-miR-195-5p, E2F7, and CEP55. CCK-8 assay was used to analyze the half-maximal inhibitory concentration (IC50) and cell proliferation ability of LUAD cells after gemcitabine treatment. Apoptosis was detected by flow cytometry. Apoptosis/autophagy markers and LC3 aggregation were detected by western blot and immunofluorescence, respectively. Finally, the mouse transplantation model was constructed to verify the regulation mechanism in vivo. In LUAD cells and tissues, E2F7 and CEP55 were highly expressed, while has-miR-195-5p was relatively less expressed. The ChIP or dual-luciferase assays demonstrated the binding relationships of E2F7 to the CEP55 promoter region and has-miR-195-5p to the 3'-UTR of E2F7. Cell experiments demonstrated that overexpression of hsa-miR-195-5p stimulated LUAD cell apoptosis and inhibited autophagy and gemcitabine resistance, while further overexpression E2F7/CEP55 could reverse the impact by hsa-miR-195-5p overexpression. In vivo experiments identified that hsa-miR-195-5p/E2F7/CEP55 axis constrained the growth of LUAD tumor. Hsa-miR-195-5p promoted apoptosis, repressed proliferation, and autophagy via E2F7/CEP55 and reduced gemcitabine resistance in LUAD, indicating that hsa-miR-195-5p/E2F7/CEP55 may be a novel target for LUAD.

ATP-citrate lyase B (ACLB) negatively affects cell death and resistance to Verticillium wilt.

BACKGROUND: ATP-citrate lyase (ACL) plays a pivotal role in histone acetylation and aerobic glycolysis. In plant, ACL is a heteromeric enzyme composed of ACLA (45 kD) and ACLB (65 kD). So far, the function of ACL genes in cotton still remains unknown. RESULTS: Here, we identified three ACLA homologous sequences and two ACLB homologous in each genome/sub-genome of cotton species. Silencing ACLB in cotton led to cell death at newly-grown leaves and stem apexes. Simultaneously, in ACLB-silenced plants, transcription factors related to senescence including SGR, WRKY23 and Osl57 were observed to be activated. Further investigation showed that excessive H2O2 was accumulated, salicylic acid-dependent defense response and pathogenesis-related gene expressions were evidently enhanced in ACLB-silenced plants, implying that knockdown of ACLB genes leads to hypersensitive response-like cell death in cotton seedlings. However, as noted, serious cell death happened in newly-grown leaves and stem apexes in ACLB-silenced plants, which led to the failure of subsequent fungal pathogenicity assays. To confirm the role of ACLB gene in regulating plant immune response, the dicotyledonous model plant Arabidopsis was selected for functional verification of ACLB gene. Our results indicate the resistance to Verticillium dahliae infection in the Arabidopsis mutant aclb-2 were enhanced without causing strong cell death. Ectopic expression of GausACLB-2 in Arabidopsis weakened its resistance to V. dahliae either in Col-0 or in aclb-2 background, in which the expression level of ACLB is negatively correlated with the resistance to V. dahliae. CONCLUSIONS: These results indicate that ACLB has a new function in negatively affecting the induction of plant defense response and cell death in cotton, which provides theoretical guidance for developing cotton varieties with resistance against Verticillium wilt.

Mechanistic Insights into the Selectivity of Norcarane Oxidation by Oxo-Manganese(V) Porphyrin Complexes.

Oxo-Mn(V) porphyrin complexes perform competitive hydroxylation, desaturation, and radical rearrangement reactions using diagnostic substrate norcarane. Initial C-H cleavage proceeds through the two hydrogen abstraction steps from the two adjacent carbon on the norcarane and then through selective reactions various products are generated. Using density functional theory calculations, we show that the hydroxylation and desaturation reactions are triggered by a rate-determining H-abstraction step, whereas the rate-determining step for the radical rearrangement is located at the rebound step (TS2). We find that the endo-2 reaction is favorable over other reactions, which is consistent with the experimental result. Furthermore, the competitive pathways for norcarane oxidation depend on the non-covalent interaction between norcarane and the porphyrin-ring, and orbital energy gaps between donor and acceptor orbitals because of stable or unstable acceptor orbital. The stereo- and regio-selectivities of norcarane oxidation are hardly sensitive to the zero-point energy and thermal free energy corrections.

Construction of a prognostic risk assessment model for lung adenocarcinoma based on Integrin ß family-related genes.

BACKGROUND: Integrin ß (ITGB) superfamily plays an essential role in the intercellular connection and signal transmission. It was exhibited that overexpressing of ITGB family members promotes the malignant progression of lung adenocarcinoma (LUAD), but the relationship between ITGB superfamily and the LUAD prognosis remains unclear. METHODS: In this study, the samples were assigned to different subgroups utilizing non-negative matrix factorization clustering according to the expression of ITGB family members in LUAD. Kaplan-Meier (K-M) survival analysis revealed the significant differences in the prognosis between different ITGB subgroups. Subsequently, we screened differentially expressed genes among different subgroups and conducted univariate Cox analysis, random forest feature selection, and multivariate Cox analysis. 9-feature genes (FAM83A, AKAP12, PKP2, CYP17A1, GJB3, TMPRSS11F, KRT81, MARCH4, and STC1) in the ITGB superfamily were selected to establish a prognostic assessment model for LAUD. RESULTS: In accordance with the median risk score, LUAD samples were divided into high- and low-risk groups. The receiver operating characteristic (ROC) curve of LUAD patients' survival was predicted via K-M survival curve and principal component analysis dimensionality reduction. This model was found to have a favorable performance in LUAD prognostic assessment. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of differentially expressed genes between groups and Gene Set Enrichment Analysis (GSEA) of intergroup samples confirmed that the high- and low-risk groups had evident differences mainly in the function of extracellular matrix (ECM) interaction. Risk score and univariate and multivariate Cox regression analyses of clinical factors showed that the prognostic model could be applied as an independent prognostic factor for LUAD. Then, we draw the nomogram of 1-, 3-, and 5-year survival of LUAD patients predicted with the risk score and clinical factors. Calibration curve and clinical decision curve proved the favorable predictive ability of nomogram. CONCLUSION: We constructed a LUAD prognostic risk model based on the ITGB superfamily, which can provide guidance for clinicians on their prognostic judgment.

COVID-19 lockdown introduces human mobility pattern changes for both Guangdong-Hong Kong-Macao greater bay area and the San Francisco bay area.

In response to the coronavirus disease 2019 (COVID-19) pandemic, various countries have sought to control COVID-19 transmission by introducing non-pharmaceutical interventions. Restricting population mobility, by introducing social distancing, is one of the most widely used non-pharmaceutical interventions. Although similar population mobility restriction interventions were introduced, their impacts on COVID-19 transmission are often inconsistent across different regions and different time periods. These differences may provide critical information for tailoring COVID-19 control strategies. In this paper, anonymized high spatiotemporal resolution mobile-phone location data were employed to empirically analyze and quantify the impact of lockdowns on population mobility. Both the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) in China and the San Francisco Bay Area (SBA) in the United States were studied. In response to the lockdowns, a general reduction in population mobility was observed, but the structural changes in mobility are very different between the two bays: 1) GBA mobility decreased by approximately 74.0-80.1% while the decrease of SBA was about 25.0-42.1%; 2) compared to SBA, the GBA had smoother volatility in daily volume during the lockdown. The volatility change indexes for GBA and SBA were 2.55% and 7.52%, respectively; 3) the effect of lockdown on short- to long-distance mobility was similar in GBA while the medium- and long-distance impact was more pronounced in SBA.

Insights into the electronic structure and mechanism of norcarane hydroxylation by OxoMn(V) porphyrin complexes: A density functional theory study.

Norcarane hydroxylation by neutral [PorMn(V)O-L] (L═OH- , F- ) and cationic [PorMn(V)O-L]+ (L═H2 O, imidazole) oxoMn(V) porphyrin complex models has been investigated by density functional theory calculations to better understand the reaction mechanism and electronic structure. We found that the energy barriers of norcarane hydroxylation by cationic oxoMn(V) porphyrin complexes are lower than those by neutral oxoMn(V) porphyrin complexes. This indicates that cationic oxoMn(V) porphyrin complexes enhance norcarane hydroxylation compared with neutral oxoMn(V) porphyrin complexes. According to electronic structure analysis, in the C─H activation step, electron transfer occurs through initial interaction between the σCH and rich-oxygen π(Mn═O) orbitals to form real donor orbitals, followed by transfer to the acceptor π*(Mn═O) orbitals. Moreover, single electron shifts from norcarane (CH) to Mn atom during C─H activation. The positive charge of the cationic complex stabilizes the acceptor orbital more than the donor orbital, reducing the energy gap between these orbitals, thus lowering the reaction barrier.

Rate-Limiting Step of Epoxidation Reaction of the Oxoiron(IV) Porphyrin π-Cation Radical Complex: Electron Transfer Coupled Bond Formation Mechanism.

Epoxidation reactions catalyzed by high-valent metal-oxo species are key reactions in various biological and chemical processes. Because the redox potentials of alkenes are higher than those of most high-valent metal-oxo species, the electron transfer (ET) from the alkene to the high-valent metal-oxo species in the epoxidation reaction is endergonic and must be coupled with another exergonic process. To reveal the mechanism of the ET, we performed a Marcus plot analysis for the epoxidation reaction of the oxoiron(IV) porphyrin π-cation radical complex (compound I) with alkene. The Marcus plots can be simulated with a linear line with the gradient of 0.50 when the redox potential of compound I varies and 0.07 when the redox potential of alkene varies. These results indicate that the ET process is involved in the rate-limiting step and coupled with the following O-C bond formation process: ET coupled bond formation mechanism. The DFT calculations support this conclusion and disclose the details of the mechanism. As the alkene comes close to the oxo ligand, the energy of the highest occupied molecular orbital (HOMO) of the alkene increases and the energy for the ET becomes small enough to allow the ET. Finally, the ET occurs from the HOMO of the alkene to the porphyrin π-radical orbital. The shift of one electron from the HOMO of the alkene by the ET simultaneously results in the O-C half bond formation between the oxo ligand and the alkene. The ET process itself is still endergonic and reversible, but the bond formation coupled with the ET changes the overall process to exergonic and irreversible. We also discuss the similarity with the aromatic hydroxylation reaction and the relevance to the epoxidation reactions of other metal-oxo complexes and peracid.

YAP/TAZ affects the development of pulmonary fibrosis by regulating multiple signaling pathways.

YAP and TAZ are important co-activators of various biological processes in human body. YAP/TAZ plays a vital role in the development of pulmonary fibrosis. Dysregulation of the YAP/TAZ signaling pathway is one of the most important causes of pulmonary fibrosis. Therefore, considering its crucial role, summary of the signal mechanism of YAP/TAZ is of certain guiding significance for the research of YAP/TAZ as a therapeutic target. The present review provided a detailed introduction to various YAP/TAZ-related signaling pathways and clarified the specific role of YAP/TAZ in these pathways. In the meantime, we summarized and evaluated possible applications of YAP/TAZ in the treatment of pulmonary fibrosis. Overall, our study is of guiding significance for future research on the functional mechanism of YAP/TAZ underlying lung diseases as well as for identification of novel therapeutic targets specific to pulmonary fibrosis.

DFT insight into axial ligand effects on electronic structure and mechanistic reactivity of oxoiron(iv) porphyrin.

A series of DFT studies on the epoxidation reactions of olefins by oxoiron(iv) porphyrin cation radical complexes are performed in this work, to elucidate the axial ligand effects on the electronic features and reaction mechanism in detail. We analyzed the molecular orbitals, spin populations, and Mulliken charges along the intrinsic reaction coordinate route. From the findings, we confirmed that the interaction between the axial ligand and the oxoiron(iv) porphyrin is strong and the initial changes in the electronic structures occur early during the reaction, which further enhances the reactivity toward olefin epoxidation. More importantly, the patterns of the electron transfer from olefin to oxoiron(iv) porphyrin were impacted by the axial ligand. The pattern of successive electron transfer from Fe-O to porphyrin and then from C[double bond, length as m-dash]C to Fe-O for oxoiron(iv) porphyrin in case of fluorine and acetate axial ligands, whereas the pattern of electron transfer occurs from C[double bond, length as m-dash]C to porphyrin for oxoiron(iv) porphyrin in case of chlorine and nitrate axial ligands during the epoxidation reaction of the olefins. We also determined the intersystem crossing between the quartet and sextet spin states occurring at the second transition state (TS2) by the analysis of the two-dimensional potential energy surface.

Substitution effects on olefin epoxidation catalyzed by Oxoiron(IV) porphyrin π-cation radical complexes: A dft study.

The effects of peripheral fluorine atoms on epoxidation reactions of ethylene by oxoiron(IV) porphyrin cation radical complex in the quartet and sextet spin multiplicities are systematically investigated using the DFT method. The overall reaction routes are determined using a model system of ethylene and Fe(IV)OCl-porphyrin with substituted fluorine atoms. By obtaining the energy diagrams and electron- and spin-density difference contour maps of the transition states and intermediate compounds, we confirm that the electron-withdrawing by peripheral fluorine atoms enhances the reactivity as the number of fluorine atoms increases, as is observed experimentally. The intersystem crossing between the quartet and sextet spin multiplicities is discussed by means of the intrinsic reaction coordinate method. We conclude that the rate-determining step is located at the first transition state (TS1) for the activation of CC and FeO bonds, and the ground electronic state changes from quartet to sextet around the TS1. © 2019 Wiley Periodicals, Inc.

Catalytic performance of bis(imino)pyridine Fe/Co complexes toward ethylene polymerization by 2D-/3D-QSPR modeling.

The two-dimensional and three-dimensional quantitative structure-property relationship (2D- and 3D-QSPR) approaches are applied to investigate the catalytic performance for a total data set of 55 bis(imino)pryridine iron and cobalt complexes, including the catalytic activity, molecular weight, and melting temperature of the product. The obtained models for the catalytic performance of interest exhibit good results by both 2D- and 3D-QSPR modeling, meanwhile higher predictive and validation powers observed in the 3D type. The modeling results indicate that the bulky substituents on ortho-position of the singular side phenyl ring and positive charge on para-position of the phenyl ring within the ligand are favorable to catalytic activity, while unfavorable to the molecular weight of product. Based on the obtained QSPR models, four new complexes are designed and predicted with good catalytic activity and very high molecular weight, which are in good agreement with our recent experimental report. © 2019 Wiley Periodicals, Inc.

Experimental and theoretical studies of the porphyrin ligand effect on the electronic structure and reactivity of oxoiron(iv) porphyrin π-cation-radical complexes.

Oxoiron(IV) porphyrin π-cation-radical complexes (Cpd I) have been studied as models for reactive intermediates called compound I in cytochromes P450, peroxidases, and catalases. It has been well known that the electronic structure and reactivity of Cpd I are modulated by the substituted position and the electron-withdrawing ability of the substituent. However, there still remain two major questions: (1) how many electronegative halogen atoms should be introduced in the meso-phenyl group to switch the porphyrin π-cation-radical state of Cpd I? (2) How does the electron-withdrawing effect of the substituent modulate the reactivity of Cpd I? To answer these two questions, we here performed experimental and theoretical studies on the electron-withdrawing effect of the meso-substituent. We gradually increased the electron-withdrawing effect by increasing the number of fluorine atoms in the meso-phenyl group. Spectroscopic analyses of these Cpd I models reveal that the porphyrin radical state shifts from having a2u radical character to having a1u radical character with an increase in the number of the fluorine atoms in the phenyl group, and the ground state of Cpd I switches from the a2u state to the a1u state when four fluorine atoms are introduced in the meso-phenyl group. The switch of the radical state is predicted well by LC-BLYP, but not by the commonly used B3LYP. The theoretical calculations indicate that the electron-withdrawing substituent makes Cpd I more reactive by stabilizing the ferric porphyrin state (product state) more than the Cpd I state (reactant state), generating a larger free energy change in the oxygenation reaction (ΔG) of Cpd I.

Catalytic Activities of Bis(pentamethylene)pyridyl(Fe/Co) Complex Analogues in Ethylene Polymerization by Modeling Method.

The catalytic activities of α,α'-bisimino-2,3:5,6-bis(pentamethylene)pyridyl(Fe/Co) chloride analogue complexes are quantitatively investigated by the multiple linear regression analysis (MLRA) method. From the point of view of the electronic and steric effects, seven structural descriptors are selected and calculated, including the Hammett constant ( F), effective net charge ( Qeff), energy difference (Δ E), HOMO-LUMO energy gap (Δε1, Δε2), open cone angle (θ), and bite angle (ß). In order to get better model, the fitting analyses are carried out by using the combinations of four, three, two, and single descriptors. The calculation results show quite good correlation results. By using two descriptors ( Qeff, ß), the catalytic activities for both the Fe and Co complexes individually and also the variation between Fe and Co (Fe-Co) analogue system can be well predicted with correlation coefficient values over 0.934. It is found that the effective net charge ( Qeff) plays the dominant role in determining the catalytic activities for Fe and Co complexes. Furthermore, the lower values of catalytic activities in Co complexes are mainly attributed to the decreasing values of Qeff.

Surgical Resection of Giant Chest Wall Chondrosarcoma Combined with Sandwich Chest Wall Reconstruction in One Case.

INTRODUCTION: Primary chest wall tumors account for 5% of all thoracic neoplasms and 1% of all primary tumors. Chondrosarcoma is a rare solid tumor, with an annual incidence of <0.5 per million people per year. It predominantly occurs in the pelvis and femur, occasionally occurs in flat bones such as the sternum and ribs, and rarely invades lung tissue. Chest wall chondrosarcomas represent only 5-15% of all chondrosarcomas. Radical surgery often leads to a large range of chest wall defects, especially when the range exceeds 6 cm × 6 cm and involves the sternum, spine, or multiple consecutive ribs. The reconstruction of the chest wall bone should be considered to restore the integrity and stability of the chest, prevent chest wall softening and abnormal breathing, and ensure the stability of respiratory circulation. Chest wall reconstruction can help restore thoracic hardness and integrity, prevent lung hernia and abnormal breathing, while also ensuring a positive aesthetic outcome. The chest wall reconstruction includes reconstruction of the pleura, bony structures, and soft tissues. CASE REPORT: In our case of an adult male, after the resection of the third and fourth anterior rib chondrosarcoma, the common anatomical plate was shaped and fixed to the stump of the third rib with screws to ensure the stability of the thorax while retaining the mobility of the thorax. After applying hernia mesh pruning, the chest wall defect was stitched to complete the pleural reconstruction of the defect area. This procedure can effectively maintain the stability of the pleural cavity, provide more effective support for the chest wall soft tissue, and promote the recovery of upper limb function and lung function. CONCLUSION: The radical surgery of giant chest wall chondrosarcoma often leads to a large range of chest wall defects. Chest wall reconstruction needs to be carried out at the same time to restore the integrity and stability of the chest wall, to avoid chest wall softening and abnormal breathing, and to ensure the stability of respiratory circulation. Using the "sandwich" method for chest wall reconstruction, in which an anatomical plate is combined with hernia mesh and muscle soft tissue, and during which pleura, bony structure, and soft tissues are reconstructed, can provide more effective support for chest wall soft tissue, effectively prevent postoperative muscle tissue collapse, avoid postoperative abnormal breathing, and promote the recovery of postoperative upper limb function and lung function. It is a very effective method for chest wall reconstruction.

Noninvasive 3D-CT simulation versus glue injection to localize small pulmonary nodules prior to anatomical segmentectomy: a randomized controlled trial.

OBJECTIVES: This study aimed to investigate whether adding glue injection to three-dimensional computed tomography bronchography and angiography (3D-CTBA) has extra benefits to facilitate anatomical segmentectomy for pulmonary nodules. METHODS: We conducted a randomized controlled trial. The patients undergoing thoracoscopic segmentectomy assisted with 3D-CTBA simulation were enrolled. Then, they were divided into the 3D-CTBA group and the glue-labelling group who received additional computed tomography-guided percutaneous glue (2-octyl cyanoacrylate) injection to label the nodules. The primary outcome was the resection rate of the nodules, and the secondary measures included the operation time, complications and thorax drainage. RESULTS: A total of 173 patients were randomized into the 3D-CTBA group (89 patients) and glue-labelling group (84 patients) between January 2018 and March 2019. Before the segmentectomy, the patients using glue labelling recorded 5 (6.0%) cases of pneumothorax, 2 (2.4%) cases of haemothorax and 1 (1.2%) case of severe chest pain. All the surgical procedure was performed fluently and safely. The resection rate of the nodules was 100% in both groups. Furthermore, these patients demonstrated similar operation time [(141.5 ± 41.9) vs (142.1 ± 38.9) min], estimated blood loss [(111.3 ± 74.0) vs (106.0 ± 63.8) ml], duration of chest tube duration [(5.1 ± 3.0) vs (5.0 ± 3.5) days] and total drainage volume [(872.3 ± 643.1) vs (826.7 ± 806.0) ml], with a P-value of >0.05 respectively. In addition, 6 (7.1%) patients in the glue-labelling group and 6 (6.7%) patients in the 3D-CTBA group reported air leakage (>5 days) and chylothorax. CONCLUSIONS: Noninvasive 3D-CTBA alone is probably sufficient to facilitate anatomical segmentectomy. The additional invasive glue labelling could be avoided in selected patients who undergo intentional segmentectomy. CLINICAL TRIAL REGISTRATION: The trial was registered under the Chinese Clinical Trial Registry (ChiCTR). Identifier: ChiCTR1800018293, https://www.chictr.org.cn/showproj.html?proj=29345.

Catalytic Atroposelective Synthesis of Axially Chiral Heterobiaryl Oxime Ethers via the One-Step Dynamic Kinetic Condensation Reaction.

The catalytic atroposelective synthesis of axially chiral heterobiaryls was first developed through the direct one-step dynamic kinetic condensation reaction with the simple transformation of the C═O bond to the C═N bond, delivering a series of novel axially chiral heterobiaryl oxime ethers.

Oxidative DNA damage of peripheral blood polymorphonuclear leukocytes, selectively induced by chronic arsenic exposure, is associated with extent of arsenic-related skin lesions.

There is increasing evidence that oxidative stress is an important risk factor for arsenic-related diseases. Peripheral blood leukocytes constitute an important defense against microorganisms or pathogens, while the research on the impact of chronic arsenic exposure on peripheral blood leukocytes is much more limited, especially at low level arsenic exposure. The purpose of the present study was to explore whether chronic arsenic exposure affects oxidative stress of peripheral blood leukocytes and possible linkages between oxidative stress and arsenic-induced skin lesions. 75 male inhabitants recruited from an As-endemic region of China were investigated in the present study. The classification of arsenicosis was based on the degree of skin lesions. Arsenic levels were measured in drinking water and urine by Atomic Fluorescence Spectroscopy. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) was tested by Enzyme-Linked Immunosorbent Assay. 8-OHdG of peripheral blood leukocytes was evaluated using immunocytochemical staining. 8-OHdG-positive reactions were only present in polymorphonuclear leukocytes (PMNs), but not in monocytes (MNs). The 8-OHdG staining of PMN cytoplasm was observed in all investigated populations, while the 8-OHdG staining of PMN nuclei was frequently found along with the elevated amounts of cell debris in individuals with skin lesion. Urinary arsenic levels were increased in the severe skin lesion group compared with the normal group. No relationship was observed between drinking water arsenic or urine 8-OHdG and the degree of skin lesions. These findings indicated that the target and persistent oxidative stress in peripheral blood PMNs may be employed as a sensitive biomarker directly to assess adverse health effects caused by chronic exposure to lower levels of arsenic.

Involvement of CD56brightCD11c+ cells in IL-18-mediated expansion of human γδ T cells.

γδ T cells are considered to be innate lymphocytes that play an important role in host defense against tumors and infections. We recently reported that IL-18 markedly amplified γδ T cell responses to zoledronate (ZOL)/IL-2. In an extension of this finding, we analyzed the mechanism underlying the IL-18-mediated expansion of γδ T cells. After incubation of PBMCs with ZOL/IL-2/IL-18, the majority of the cells expressed γδ TCR, and the rest mostly exhibited CD56(bright)CD11c(+) under the conditions used in this study. CD56(bright)CD11c(+) cells were derived from a culture of CD56(int)CD11c(+) cells and CD14(+) cells in the presence of IL-2 and IL-18 without the addition of ZOL. They expressed IL-18Rs, HLA-DR, CD25, CD80, CD83, CD86, and CD11a/CD18. In addition, they produced IFN-γ, TNF-α, but not IL-12, when treated with IL-2/IL-18, and they exerted cytotoxicity against K562 cells, thus exhibiting characteristics of both NK cells and dendritic cells. Incubation of purified γδ T cells with CD56(bright)CD11c(+) cells in the presence of ZOL/IL-2/IL-18 resulted in the formation of massive cell clusters and led to the marked expansion of γδ T cells. However, both conventional CD56(-/int)CD11c(high) dendritic cells induced by GM-CSF/IL-4 and CD56(+)CD11c(-) NK cells failed to support the expansion of γδ T cells. These results strongly suggest that CD56(bright)CD11c(+) cells play a key role in the IL-18-mediated proliferation of γδ T cells.

Quantum Tunneling in Reactions Modulated by External Electric Fields: Reactivity and Selectivity.

Quantum tunneling and external electric fields (EEFs) can promote some reactions. However, the synergetic effect of an EEF on a tunneling-involving reaction and its temperature-dependence is not very clear. In this study, we extensively investigated how EEFs affect three reactions that involve hydrogen- or (ground- and excited-state) carbon-tunneling using reliable DFT, DLPNO-CCSD(T1), and variational transition-state theory methods. Our study revealed that oriented EEFs can significantly reduce the barrier and corresponding barrier width (and vice versa) through more electrostatic stabilization in transition states. These EEF effects enhance the nontunneling and tunneling-involving rates. Such EEF effects also decrease the crossover temperatures and quantum tunneling contribution, albeit with lower and thinner barriers. Moreover, EEFs can modulate and switch on/off the tunneling-driven 1,2-H migration of hydroxycarbenes under cryogenic conditions. Furthermore, our study predicts for the first time that EEF/tunneling synergy can control the chemo- or site-selectivity of one molecule bearing two similar/same reactive sites.