Publications by authors named "Xian Zhang"

1,107 Publications

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Promoter usage regulating the surface density of CAR molecules may modulate the kinetics of CAR-T cells .

Mol Ther Methods Clin Dev 2021 Jun 13;21:237-246. Epub 2021 Mar 13.

Hebei Senlang Biotechnology, Shijiazhuang 050000, China.

Although chimeric antigen receptor T (CAR-T) cell therapy achieves high remission rates, challenges (e.g., toxicity management and relapse prevention) remain. The major risks are cytokine release syndrome and related neurological toxicity. The influence of the CAR surface density on the efficacy/safety of CAR-T cell therapy and the factors determining CAR density were not elucidated comprehensively. Here, we discovered that the use of the MND promoter increased the transduction rate and reduced the CAR surface density. Additionally, MND-driven CAR-T cells had prolonged antileukemia activity in a mouse model. In an initial dual-armed anti-CD19 CAR-T cell pilot study (ClinicalTrials.gov: NCT03840317), eight and six subjects were infused with MND and EF1α promoter-driven autologous CAR-T cells (3 × 10 CAR-T cells/kg), respectively. MND subjects developed mild fever and lower interferon gamma (IFN-γ) concentrations than in the EF1A19 group. All but one subject in each cohort reached minimal residual disease (MRD)-negative complete remission after the first month of evaluation. These results represent the first comprehensive study on the promoter-driven modulation of CAR-T cell functionality. These findings encourage further evaluation of the potential of the MND promoter to drive CAR-T cells as a broadly applicable cellular product for anticancer immunotherapy.
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http://dx.doi.org/10.1016/j.omtm.2021.03.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8027690PMC
June 2021

Engineering Clostridium cellulovorans for highly selective n-butanol production from cellulose in consolidated bioprocessing.

Biotechnol Bioeng 2021 Apr 12. Epub 2021 Apr 12.

William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 W. Woodruff Avenue, Columbus, OH, 43210, USA.

Cellulosic n-butanol from renewable lignocellulosic biomass has gained increased interest. Previously, we have engineered Clostridium cellulovorans, a cellulolytic acidogen, to overexpress the bifunctional butyraldehyde/butanol dehydrogenase gene adhE2 from Clostridium acetobutylicum for n-butanol production from crystalline cellulose. However, butanol production by this engineered strain had a relatively low yield of ~0.22 g/g cellulose due to the co-production of ethanol and acids. We hypothesized that strengthening the carbon flux through the central butyryl-CoA biosynthesis pathway and increasing intracellular NADH availability in C. cellulovorans adhE2 would enhance n-butanol production. In this study, thiolase (thlA ) from Clostridium acetobutylicum and 3-hydroxybutyryl-CoA dehydrogenase (hbd ) from Clostridium tyrobutyricum were overexpressed in C. cellulovorans adhE2 to increase the flux from acetyl-CoA to butyryl-CoA. In addition, ferredoxin-NAD(P) oxidoreductase (fnr), which can regenerate the intracellular NAD(P)H and thus increase butanol biosynthesis, was also overexpressed. Metabolic flux analyses showed that mutants overexpressing these genes had a significantly increased carbon flux toward butyryl-CoA, which resulted in increased production of butyrate and butanol. The addition of methyl viologen as an electron carrier in batch fermentation further directed more carbon flux towards n-butanol biosynthesis due to increased reducing equivalent or NADH. The engineered strain C. cellulovorans adhE2-fnr -thlA -hbd produced n-butanol from cellulose at a 50% higher yield (0.34 g/g), the highest ever obtained in batch fermentation by any known bacterial strain. The engineered C. cellulovorans is thus a promising host for n-butanol production from cellulosic biomass in consolidated bioprocessing. This article is protected by copyright. All rights reserved.
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http://dx.doi.org/10.1002/bit.27789DOI Listing
April 2021

Enhanced production of L-arginine by improving carbamoyl phosphate supply in metabolically engineered Corynebacterium crenatum.

Appl Microbiol Biotechnol 2021 Apr 10;105(8):3265-3276. Epub 2021 Apr 10.

Key Laboratory of Industrial Biotechnology of the Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.

Carbamoyl phosphate is an important precursor for L-arginine and pyrimidines biosynthesis. In view of this importance, the cell factory should enhance carbamoyl phosphate synthesis to improve related compound production. In this work, we verified that carbamoyl phosphate is essential for L-arginine production in Corynebacterium sp., followed by engineering of carbamoyl phosphate synthesis for further strain improvement. First, carAB encoding carbamoyl phosphate synthetase II was overexpressed to improve the synthesis of carbamoyl phosphate. Second, the regulation of glutamine synthetase increases the supply of L-glutamine, providing an effective substrate for carbamoyl phosphate synthetase II. Third, carbamate kinase, which catalyzes inorganic ammonia synthesis carbamoyl phosphate, was screened and selected to assist in carbamoyl phosphate supply. Finally, we disrupted ldh (encoding lactate dehydrogenase) to decrease by-production formation and save NADH to regenerate ATP through the electron transport chain. Subsequently, the resulting strain allowed a dramatically increased L-arginine production of 68.6 ± 1.2 g∙L, with an overall productivity of 0.71 ± 0.01 g∙L∙h in 5-L bioreactor. Stepwise rational metabolic engineering based on an increase in the supply of carbamoyl phosphate resulted in a gradual increase in L-arginine production. The strategy described here can also be implemented to improve L-arginine and pyrimidine derivatives. KEY POINTS: • The L-arginine production strongly depended on the supply of carbamoyl phosphate. • The novel carbamoyl phosphate synthesis pathway for C. crenatum based on carbamate kinase was first applied to L-arginine synthesis. • ATP was regenerated followed with the disruption of lactate formation.
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http://dx.doi.org/10.1007/s00253-021-11242-wDOI Listing
April 2021

Fascin inhibitor increases intratumoral dendritic cell activation and anti-cancer immunity.

Cell Rep 2021 Apr;35(1):108948

Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, NY 10065, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine of Cornell University, New York, NY 10065, USA. Electronic address:

Fascin protein is the main actin-bundling protein in filopodia and invadopodia, which are critical for tumor cell migration, invasion, and metastasis. Small-molecule fascin inhibitors block tumor invasion and metastasis and increase the overall survival of tumor-bearing mice. Here, we report a finding that fascin blockade additionally reinvigorates anti-tumor immune response in syngeneic mouse models of various cancers. Fascin protein levels are increased in conventional dendritic cells (cDCs) in the tumor microenvironment. Mechanistically, fascin inhibitor NP-G2-044 increases the number of intratumoral-activated cDCs and enhances the antigen uptake by cDCs. Furthermore, together with PD-1 blocking antibody, NP-G2-044 markedly increases the number of activated CD8 T cells in the otherwise anti-PD-1 refractory tumors. Reduction of fascin levels in cDCs, but not fascin gene knockout in tumor cells, mimics the anti-tumor immune effect of NP-G2-044. These data demonstrate that fascin inhibitor NP-G2-044 simultaneously limits tumor metastasis and reinvigorates anti-tumor immune responses.
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http://dx.doi.org/10.1016/j.celrep.2021.108948DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8050791PMC
April 2021

Transmission and imaging characteristics of flexible gradually tapered waveguide at 0.3 THz.

Opt Express 2021 Mar;29(6):8430-8440

Flexible gradually tapered metal waveguides (GTMWs) are fabricated by an inner plating silver film in a polycarbonate (PC) capillary for the transmission and imaging at 0.3 THz. It was demonstrated theoretically and experimentally that GTMWs have lower transmission losses and smaller additional losses of bending, comparing with thin constant bore metal waveguides (CBMWs). Measured losses of 1.95 dB and 2.45 dB were obtained for a 1 m long GTMW with bore size varying from 2.6 mm to 1.6 mm under straight and one circle bending configuration. Measured losses were 4.48 dB/m and 7.78 dB/m for 1.6 mm bore CBMW under the same straight and bend configurations. Owing to higher energy concentration at the output, a larger penetration ability of output wave can be achieved by GTMW, which is beneficial for imaging application. A scanning imaging system was established using fabricated waveguides as the probes. Measured results show that the air slits of the order of wavelength can be clearly distinguished. An imaging system with a GTMW probe also has better performances due to lower bending loss and improved coupling efficiency.
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http://dx.doi.org/10.1364/OE.419506DOI Listing
March 2021

Strained Epitaxy of Monolayer Transition Metal Dichalcogenides for Wrinkle Arrays.

ACS Nano 2021 Apr 5. Epub 2021 Apr 5.

Department of Materials Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen 518055, P. R. China.

Wrinkling two-dimensional (2D) transition metal dichalcogenides (TMDCs) provides a mechanism to adjust the physical and chemical properties as per need. Traditionally, TMDCs wrinkles achieved by transferring exfoliated materials on prestretched polymer suffer from poor control and limited sample area, which significantly hinders desirable applications. Herein, we fabricate large-area monolayer TMDCs wrinkle arrays directly on the -quartz substrate using strained epitaxy. The uniaxial thermal expansion coefficient mismatch between the substrate and TMDCs materials enables the generation of large uniaxial thermal strain. By quenching the TMDCs after growth, this uniaxial thermal strain can be quickly released as a form of wrinkle arrays along the [0001] direction. Using WS as a model system, the size of as-grown wrinkles can be finely modulated within sub-100 nm by changing the quenching temperature. These WS wrinkles can be locally folded and form various multilayer structures with odd layer numbers during the transfer process. Besides, the corrugated structures in WS wrinkles induce significant changes to optical properties including anisotropic Raman response, enhanced photoluminescence, and second harmonic generation emissions. Furthermore, these wrinkle arrays exhibit enhanced chemical reactivity that can be selectively engineered to ribbon arrays with improved electrocatalytic performance. The developed strategy of strained epitaxy here should enable flexibility in the design of more sophisticated 2D-based structures, offering a simple but effective way toward the modulation of properties with enhanced performances.
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http://dx.doi.org/10.1021/acsnano.0c09983DOI Listing
April 2021

Composite Polymer Anion Exchange Membranes with Sandwich Structure and Improved Performance for Zn-Air Battery.

Membranes (Basel) 2021 Mar 22;11(3). Epub 2021 Mar 22.

School of Materials Science & Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.

In this study, we fabricated a composite polymer anion exchange membrane (AEM) with a sandwich structure. This prepared AEM demonstrated high ionic conductivity (0.25 Scm), excellent alkali resistance (8 M KOH), and good mechanical properties (tensile strength of 0.455 MPa and elongation at break of 82.13%). Here, degrease cotton (DC) treated with LiOH/urea aqueous solution was used and immersed into a coagulation bath to form a film. This film was immersed in acrylic acid (AA) monomers, and in-suit polymerization was carried out in the presence of KOH and an initiator. Finally, a composite polymer membrane with sandwich structure was achieved, in which the upper and bottom layers were mainly composed of polymerized AA (PAA) while the central layer was mainly composed of DC derived film. The central layer acted as a skeleton to improve the mechanical properties and alkali resistance. The top and bottom layers (PAA-rich layers) acted as OH- ion transport carriers, making basic cations migrate along the main chain of PAA. This newly developed composite membrane showed increased tensile strength and an elongation at break of 2.7 and 1.5 times, respectively, when compared to a control PAA/KOH AEM film. Furthermore, an electrochemical stability window of 2.0 V was measured via the cyclic voltammetry curve test, showing a wide electrochemical window and promising application in Zn-Air batteries.
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http://dx.doi.org/10.3390/membranes11030224DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8004831PMC
March 2021

[Advances in stress tolerance mechanisms and synthetic biology for the industrial robustness of Corynebacterium glutamicum].

Sheng Wu Gong Cheng Xue Bao 2021 Mar;37(3):831-845

Key Laboratory of Industrial Biotechnology, Ministry, of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, Jiangsu, China.

As a model industrial host and microorganism with the generally regarded as safe (GRAS) status, Corynebacterium glutamicum not only produces amino acids on a large scale in the fermentation industry, but also has the potential to produce various new products. C. glutamicum usually encounters various stresses in the process of producing compounds, which severely affect cell viability and production performance. The development of synthetic biology provides new technical means for improving the robustness of C. glutamicum. In this review, we discuss the tolerance mechanisms of C. glutamicum to various stresses in the fermentation process. At the same time, we highlight new synthetic biology strategies for boosting C. glutamicum robustness, including discovering new stress-resistant elements, modifying transcription factors, and using adaptive evolution strategies to mine stress-resistant functional modules. Finally, prospects of improving the robustness of engineered C. glutamicum strains ware provided, with an emphasis on biosensor, screening and design of transcription factors, and utilizing the multiple regulatory elements.
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http://dx.doi.org/10.13345/j.cjb.200631DOI Listing
March 2021

Association of FOXP3 gene polymorphisms with chronic immune thrombocytopenia in a Chinese Han population.

Int J Lab Hematol 2021 Mar 24. Epub 2021 Mar 24.

State Key Laboratory of Experimental Hematology, National Clinical Research Center for Hematological disorders, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China.

Introduction: Forkhead box P3 (Foxp3) is encoded by the human FOXP3, an X-chromosome gene, and is a transcription factor that regulates regulatory T-cell (Treg) development and function. FOXP3 gene polymorphisms have recently been investigated as candidate risk factors in various autoimmune diseases. This study aimed to investigate the possible influence of FOXP3 gene polymorphisms on genetic predisposition to chronic immune thrombocytopenia (ITP).

Methods: The study cohort comprised 329 chronic ITP patients and 279 healthy controls, who were genotyped for three polymorphisms in the promoter region of FOXP3 gene, -6054 del/ATT, -3279 A/C, and -924 A/G.

Results: Of the three polymorphisms identified, the -3279 AA genotype was more frequent in female patients with chronic ITP than in female controls (P = .035, OR 0.434, 95% CI 0.223-0.846), and the -3279 A carrier was shown to be associated with the risk of chronic ITP in female cohort (P = .003, OR 0.610, 95% CI 0.437-0.851). Furthermore, the female patients with chronic ITP had remarkably more frequent haplotype -6054 del/-3279 A/-924 A (P = .027, OR 3.584, 95% CI 1.148-11.186) and less haplotype -6054 del/-3279 C/-924 G (P = .039, OR 0.445, 95% CI 0.204-0.973) in comparison with female healthy controls. Although there were no significant differences in the male cohort, when the combined alleles and haplotypes of the two genders were analyzed, the results obtained were similar to those of females.

Conclusion: According to our data, the -3279 A/C polymorphism of FOXP3 gene may be associated with the susceptibility to chronic ITP in Chinese Han population.
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http://dx.doi.org/10.1111/ijlh.13525DOI Listing
March 2021

Impact of MASP2 gene polymorphism and gene-tea drinking interaction on susceptibility to tuberculosis.

Sci Rep 2021 Mar 22;11(1):6544. Epub 2021 Mar 22.

Department of Epidemiology and Health Statistics, Xiangya School of Public Health, Central South University, 110 Xiangya Road, Changsha, 410000, China.

Mannan-binding lectin-associated serine protease-2 (MASP-2) has been reported to play an important role as a key enzyme in the lectin pathway of the complement system. The objectives of our study were to determine whether the single-nucleotide polymorphism (SNPs) of MASP2 and the gene-tea drinking interaction were associated with the susceptibility to TB. In total, 503 patients and 494 healthy controls were contained. Three SNPs (rs12142107, rs12711521, and rs7548659) were genotyped. The association between the SNPs and susceptibility to TB were investigated by conducting multivariate unconditional logistic regression analysis. The gene-tea drinking interactions were analyzed by the additive model of marginal structural linear odds models. Both genotype AC + AA at rs12711521 of MASP2 genes and genotype GT + GG at rs7548659 of MASP2 genes were more prevalent in the TB patient group than the healthy control group (OR: 1.423 and 1.439, respectively, P < 0.05). In addition, The relative excess risk of interaction (RERI) between tea drinking and rs12142107, rs12711521, and rs7548659 of MASP2 genes was found to suggest negative interactions, which reached - 0.2311 (95% confidence interval (CI): - 0.4736, - 0.0113), - 0.7080 (95% CI - 1.3998, - 0.0163), and - 0.5140 (95% CI - 0.8988, - 0.1291), respectively (P < 0.05). Our finding indicated that the SNPs (rs12711521 and rs7548659) of MASP2 were associated with the susceptibility to TB. Furthermore, there were negative interactions between tea drinking and rs12142107, rs12711521, and rs75548659 of MASP2 gene, respectively. Our research provides a basis for studying the pathogenesis and prevention of tuberculosis.
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http://dx.doi.org/10.1038/s41598-021-86129-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7985323PMC
March 2021

Methyl jasmonate mediates melatonin-induced cold tolerance of grafted watermelon plants.

Hortic Res 2021 Mar 10;8(1):57. Epub 2021 Mar 10.

State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, 712100, Yangling, Shaanxi, China.

Root-shoot communication has a critical role in plant adaptation to environmental stress. Grafting is widely applied to enhance the abiotic stress tolerance of many horticultural crop species; however, the signal transduction mechanism involved in this tolerance remains unknown. Here, we show that pumpkin- or figleaf gourd rootstock-enhanced cold tolerance of watermelon shoots is accompanied by increases in the accumulation of melatonin, methyl jasmonate (MeJA), and hydrogen peroxide (HO). Increased melatonin levels in leaves were associated with both increased melatonin in rootstocks and MeJA-induced melatonin biosynthesis in leaves of plants under cold stress. Exogenous melatonin increased the accumulation of MeJA and HO and enhanced cold tolerance, while inhibition of melatonin accumulation attenuated rootstock-induced MeJA and HO accumulation and cold tolerance. MeJA application induced HO accumulation and cold tolerance, but inhibition of JA biosynthesis abolished rootstock- or melatonin-induced HO accumulation and cold tolerance. Additionally, inhibition of HO production attenuated MeJA-induced tolerance to cold stress. Taken together, our results suggest that melatonin is involved in grafting-induced cold tolerance by inducing the accumulation of MeJA and HO. MeJA subsequently increases melatonin accumulation, forming a self-amplifying feedback loop that leads to increased HO accumulation and cold tolerance. This study reveals a novel regulatory mechanism of rootstock-induced cold tolerance.
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http://dx.doi.org/10.1038/s41438-021-00496-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7943586PMC
March 2021

Effect of thiamazole on kainic acid-induced seizures in mice.

Saudi J Biol Sci 2021 Mar 28;28(3):1840-1846. Epub 2020 Dec 28.

Department of Biochemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.

Kainic acid (KA) induced epileptic seizures in mice is a commonly used experimental model of epilepsy. Previous studies have suggested the roles of various neurotransmitters and oxidative stress in KA-induced seizures. An important role of hypothyroidism has also been suggested in epilepsy. Thiamazole (TZ) is an anti-hyperthyroid drug with antioxidant property. This study reports the effect of TZ on KA-induced epileptic seizures in mice, produced by intraperitoneal (IP) injection of KA (18 mg/kg). Prior to KA injection, the animals were treated with TZ (12.5, 25 and 50 mg/kg IP). Our results showed that in KA alone group, about half of the animals developed seizures. Pre-treatment of mice with TZ significantly increased the frequency of seizures in dose-dependent manner. Administration of TZ significantly reduced the latency time and aggravated the severity of seizures. TZ also increased the mortality in KA-treated mice. Striatal dopamine and serotonin levels were markedly increased in KA alone treated mice, which were not significantly affected by TZ treatment. Among the indices of oxidative stress, we observed a significant reduction in cerebral vitamin E whereas the levels of cerebral malondialdehyde and conjugated dienes were significantly increased in animals with high severity of seizures. In conclusion, TZ potentiated the frequency and severity of experimental seizure in mice. There is a possibility of altered metabolism of KA in presence of TZ that might have potentiated the toxicity of KA. These findings suggest a caution while administering anti-hyperthyroid drugs in epileptic seizures.
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http://dx.doi.org/10.1016/j.sjbs.2020.12.033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7938111PMC
March 2021

The Arabidopsis MATERNAL EFFECT EMBRYO ARREST45 Protein Modulates Maternal Auxin Biosynthesis and Controls Seed Size by Inducing AINTEGUMENTA.

Plant Cell 2021 Mar 17. Epub 2021 Mar 17.

State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018, Shandong, China.

Seed size is a major factor determining crop yields that is controlled through the coordinated development of maternal and zygotic tissues. Here, we identified Arabidopsis MATERNAL EFFECT EMBRYO ARREST45 (MEE45) as a B3 transcription factor that controls cell proliferation and maternally regulates seed size through its transcriptional activation of AINTEGUMENTA (ANT) and its downstream control of auxin biosynthesis in the ovule integument. After characterizing reduced seed and organ size phenotypes in mee45 mutants and finding that overexpression of MEE45 causes oversized seeds, we discovered that the MEE45 protein can bind to the promoter region of the ANT locus and positively regulate its transcription. ANT in-turn activates expression of auxin biosynthetic genes (e.g., YUCCA4) in the ovule integument. Our results thus illustrate mechanisms underlying maternal tissue-mediated regulation of seed size and suggest that MEE45 and its downstream components can be harnessed to develop higher yielding crop varieties.
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http://dx.doi.org/10.1093/plcell/koab084DOI Listing
March 2021

Association of Small Intestinal Bacterial Overgrowth With Heart Failure and Its Prediction for Short-Term Outcomes.

J Am Heart Assoc 2021 Apr 17;10(7):e015292. Epub 2021 Mar 17.

Department of Cardiology Shanghai Institute of Cardiovascular DiseasesZhongshan HospitalFudan University Shanghai China.

Background Small intestinal bacterial overgrowth (SIBO) is a common pathological condition of intestinal microbiota. The prevalence of SIBO and its prognostic value in patients with heart failure (HF) are unknown. Methods and Results A total of 287 patients tested for SIBO using lactulose hydrogen-methane breath test were evaluated. At least 1 of the following criteria fulfilled was SIBO positive: patients with fasting hydrogen level ≥20 parts per million (ppm) or a ≥20 ppm rise in hydrogen by 90 minutes were diagnosed with SIBO (H) positive; and patients with methane levels ≥10 ppm at any test point were diagnosed with SIBO (CH) positive. The association between SIBO and the composite of cardiovascular death and HF rehospitalization was investigated. In 287 consecutive patients with HF, 128 (45%) were positive for SIBO. Our result showed SIBO increased the risk of HF rehospitalization in patients with HF with reduced ejection fraction (<0.001), and the risk of cardiovascular death in patients with HF with preserved EF (=0.011). SIBO was an independent risk factor of primary end point in patients with HF (hazard ratio [HR], 2.13; 95% CI; 1.26-3.58; =0.005). In addition, SIBO (CH) showed a prognostic value on adverse outcomes (HR, 2.35; 95% CI, 1.38-4.02; <0.001), whereas the association between SIBO (H) and outcomes was not statistically significant. Conclusions There was high prevalence of SIBO in patients with HF, and SIBO was independently associated with poor outcomes. Proactive treatment for SIBO may provide extra benefit for patients with HF.
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http://dx.doi.org/10.1161/JAHA.119.015292DOI Listing
April 2021

Experimental and Computational Investigation of Layer-Dependent Thermal Conductivities and Interfacial Thermal Conductance of One- to Three-Layer WSe.

ACS Appl Mater Interfaces 2021 Mar 15;13(11):13063-13071. Epub 2021 Mar 15.

Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, United States.

Two-dimensional materials such as graphene and transition metal dichalcogenides (TMDCs) have received extensive research interest and investigations in the past decade. In this research, we used a refined opto-thermal Raman technique to explore the thermal transport properties of one popular TMDC material WSe, in the single-layer (1L), bilayer (2L), and trilayer (3L) forms. This measurement technique is direct without additional processing to the material, and the absorption coefficient of WSe is discovered during the measurement process to further increase this technique's precision. By comparing the sample's Raman spectroscopy spectra through two different laser spot sizes, we are able to obtain two parameters-lateral thermal conductivities of 1L-3L WSe and the interfacial thermal conductance between 1L-3L WSe and the substrate. We also implemented full-atom nonequilibrium molecular dynamics simulations (NEMD) to computationally investigate the thermal conductivities of 1L-3L WSe to provide comprehensive evidence and confirm the experimental results. The trend of the layer-dependent lateral thermal conductivities and interfacial thermal conductance of 1L-3L WSe is discovered. The room-temperature thermal conductivities for 1L-3L WSe are 37 ± 12, 24 ± 12, and 20 ± 6 W/(m·K), respectively. The suspended 1L WSe possesses a thermal conductivity of 49 ± 14 W/(m·K). Crucially, the interfacial thermal conductance values between 1L-3L WSe and the substrate are found to be 2.95 ± 0.46, 3.45 ± 0.50, and 3.46 ± 0.45 MW/(m·K), respectively, with a flattened trend starting the 2L, a finding that provides the key information for thermal management and thermoelectric designs.
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http://dx.doi.org/10.1021/acsami.0c21045DOI Listing
March 2021

Stigmasterol Simultaneously Induces Apoptosis and Protective Autophagy by Inhibiting Akt/mTOR Pathway in Gastric Cancer Cells.

Front Oncol 2021 23;11:629008. Epub 2021 Feb 23.

Key Laboratory of Tropical Translational Medicine of the Ministry of Education & Hainan Provincial Key Laboratory of Tropical Medicine, Hainan Medical University, Haikou, China.

Background: Stigmasterol (SS) has been proven to possess potential anticancer activities in several cancer cell lines, but its molecular mechanism is still unknown. Thus, we investigated whether SS has the capabilities of inducing autophagy and its molecular mechanisms in gastric cancer cells.

Methods: We used CCK8 assay, clone formation assay, and EdU proliferation assay to assess the effects of SS on cell proliferation in SGC-7901 and MGC-803 cells , and its inhibition on the tumor growth of gastric cancer was observed . Apoptosis induced by SS was demonstrated using Hoechst and TUNEL staining, annexin V-FITC/PI assay. Immunofluorescence staining is used to detect the formation of autophagosomes triggered by SS. Apoptosis and autophagy related proteins were analyzed by western blot.

Results: The results indicated that SS treatment inhibited cell proliferation in SGC-7901 and MGC-803 cells. Furthermore, SS treatment induced apoptosis and autophagy by blocking Akt/mTOR signaling pathway. The pretreatment with the Akt inhibitor MK-2206 could promote apoptosis and autophagy induced by SS, predicting that Akt/mTOR pathway is involved in SS-induced apoptosis and autophagy. In addition, blockade of autophagy with 3-MA (an inhibitor of autophagy) enhanced SS-induced apoptosis in SGC-7901 and MGC-803 cells, implying that autophagy mediated by SS plays a cytoprotective role against apoptosis. Finally, an study demonstrated that tumor growth of gastric cancer was suppressed by SS in a xenograft model.

Conclusion: Our findings illustrate for the first time that SS simultaneously induces apoptosis and protective autophagy by inhibiting Akt/mTOR pathway in gastric cancer cells, and SS may become a potential anticancer drug in treating gastric cancer in the future.
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http://dx.doi.org/10.3389/fonc.2021.629008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7940753PMC
February 2021

Comparative Analysis, Characterization and Evolutionary Study of Dirigent Gene Family in Cucurbitaceae and Expression of Novel Dirigent Peptide against Powdery Mildew Stress.

Genes (Basel) 2021 Feb 24;12(3). Epub 2021 Feb 24.

State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, China.

Dirigent (DIR) proteins are induced under various stress conditions and involved in sterio- and regio-selective coupling of monolignol. A striking lack of information about dirigent genes in cucurbitaceae plants underscores the importance of functional characterization. In this study, 112 DIR genes were identified in six species, and 61 genes from major cultivated species were analyzed. DIRs were analyzed using various bioinformatics tools and complemented by expression profiling. Phylogenetic analysis segregated the putative DIRs into six distinctively known subgroups. Chromosomal mapping revealed uneven distribution of genes, whereas synteny analysis exhibited that duplication events occurred during gene evolution. Gene structure analysis suggested the gain of introns during gene diversification. Gene ontology (GO) enrichment analysis indicates the participation of proteins in lignification and pathogen resistance activities. We also determined their organ-specific expression levels in three species revealing preferential expression in root and leaves. Furthermore, the number of CmDIR (, , and ) and ClDIR (, , , and ) genes exhibited higher expression in resistant cultivars after powdery mildew (PM) inoculation. In summary, based on the expression and in-silico analysis, we propose a role of DIRs in disease resistance mechanisms.
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http://dx.doi.org/10.3390/genes12030326DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7996225PMC
February 2021

Semi-quantitative activity assays for high-throughput screening of higher activity gamma glutamyl transferase and enzyme immobilization to efficiently synthesize L-theanine.

J Biotechnol 2021 Mar 24;330:9-16. Epub 2021 Feb 24.

The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, China. Electronic address:

The bio-production of theanine is currently of significant interest due to its wide applications in food and healthcare products. Gamma glutamyl transferase (GGT) has been widely applied in L-theanine synthesis, but L-theanine yields remain prohibitively low for commercial production. In this study, a robust high-throughput screening process for isolating GGT mutants was developed through a combination of error-prone PCR techniques and a colorimetric reaction. The co-expression of PrsA lipoprotein enhances the secretion of GGT, thus GGT could be obtained quickly and easily without crushing cells. Random mutations on ggt genes were introduced by using error-prone PCR kits to build a large mutant library. A colorless compound generated by the reaction between NH (released from L-theanine synthesis) and OPA was measured quantitatively by UV/visible spectroscopy when mixed with TCA and DMSO. Approximately 30 positive clones with improved color formation on the 96-well plates were identified, and mutants T413P and T463S with more than by 30 % higher transpeptidation activity versus the original GGT were isolated. To improve the operational stability and economical use, mutant GGT was immobilized on a prepared oxidized cellulose nanofiber membrane. The remaining activity of immobilized GGT was 88 % versus 72 % of free enzyme over 15 h. A fed-batch conversion was performed with the immobilized GGT, and over 70 g/L L-theanine could be accumulated within 18 h after feeding twice. Versus other studies, this is one of the best L-theanine synthesis systems using immobilized GGT.
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http://dx.doi.org/10.1016/j.jbiotec.2021.02.011DOI Listing
March 2021

Rational engineering of the Plasmodium falciparuml-lactate dehydrogenase loop involved in catalytic proton transfer to improve chiral 2-hydroxybutyric acid production.

Int J Biol Macromol 2021 Feb 22;179:71-79. Epub 2021 Feb 22.

The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, China. Electronic address:

l-lactate dehydrogenases (LDHs) has been widely studied for their ability to reduce 2-keto acids for the production of 2-hydroxy acids, whereby 2-hydroxybutyric acids (2-HBA) is among the most important fundamental building blocks for synthesizing pharmaceuticals and biodegradable materials. However, LDHs usually show low activity towards 2-keto acids with longer side chain such as 2-oxobutyric acid (2-OBA). Here rational engineering of the Plasmodium falciparum LDH loop with residue involved in the catalytic proton transfer was initially studied. By combining homology alignment and structure-based design approach, we found that changing the charge characteristics or hydrogen bond network interactions of this loop could improve enzymatic catalytic activities and stabilities towards 2-OBA. Compared with wild type, variant N197D showed 1.15 times higher activity and 2.73 times higher K/Km. The half-life of variant N197D at 40 °C increased to 77.9 h compared with 50.4 h of wild type. Furthermore, asymmetric synthesis of (S)-2-HBA with coenzyme regeneration revealed 95.8 g/L production titer within 12 h for variant N197D, 2.05 times higher than using wild type. Our study indicated the importance of loop with residues involved in the catalytic proton transfer process, and the engineered LDH would be more suitable for (S)-2-HBA production.
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http://dx.doi.org/10.1016/j.ijbiomac.2021.02.144DOI Listing
February 2021

Oncogenic ZEB2/miR-637/HMGA1 signaling axis targeting vimentin promotes the malignant phenotype of glioma.

Mol Ther Nucleic Acids 2021 Mar 5;23:769-782. Epub 2021 Jan 5.

Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, 510375, People's Republic of China.

Glioma is the most common primary tumor of the central nervous system. We previously confirmed that zinc finger E-box binding homeobox (ZEB) 2 promotes the malignant progression of glioma, while microRNA-637 (miR-637) is associated with favorable prognosis in glioma. This study aimed to investigate the potential interaction between ZEB2 and miR-637 and its downstream signaling pathway in glioma. The results revealed that ZEB2 could directly bind to the E-box elements in the miR-637 promoter and promote cell proliferation, migration, and invasion via miR-637 downregulation. Subsequent screening confirmed that HMGA1 was a direct target of miR-637, while miR-637 could drive the malignant phenotype of glioma by suppressing HMGA1 both and . Furthermore, interaction between cytoplasmic HMGA1 and vimentin was observed, and vimentin inhibition could abolish increased migration and invasion induced by HMGA1 overexpression. Both HMGA1 and vimentin were associated with an unfavorable prognosis in glioma. Additionally, upregulated HMGA1 and vimentin were found in isocitrate dehydrogenase (IDH) wild-type and 1p/19q non-codeletion diffusely infiltrating glioma. In conclusion, we identified an oncogenic ZEB2/miR-637/HMGA1 signaling axis targeting vimentin that promotes both migration and invasion in glioma.
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http://dx.doi.org/10.1016/j.omtn.2020.12.029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7868719PMC
March 2021

Regulated delayed attenuation improves vaccine efficacy in preventing infection from avian pathogenic Escherichia coli O and Salmonella typhimurium.

Vet Microbiol 2021 Mar 6;254:109012. Epub 2021 Feb 6.

China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection and Internet Technology, College of Animal Science and Technology, College of Veterinary Medicine of Zhejiang A&F University, Lin'an, China. Electronic address:

Avian pathogenic Escherichia coli (APEC) O and Salmonella typhimurium (S. Typhimurium) are two leading bacterial pathogens that cause significant economic loss in the poultry industry. O-antigen is an important immunogen of these two bacteria to induce host protective immune responses during infection. To develop a bivalent vaccine against APEC O and S. Typhimurium, the attenuated Salmonella ST01 (Δasd ΔrfbP Δcrp) was genetically constructed to deliver APEC O O-antigen polysaccharide (OPS), which stably expresses OPS with asd balanced-lethal system in vitro and in vivo. After oral immunization, the recombinant attenuated Salmonella vaccine (RASV) strain ST01 (pSS26-O) provided insufficient protection against the APEC O challenge. Therefore, the regulated delayed attenuation strain ST02 (Δasd ΔrfbP ΔPcrp::TTaraC Pcrp) was further constructed by regulating cyclic AMP receptor protein (crp) with araC P cassette to better present the heterologous O-antigen to the host immune system. The innovative recombinant strain ST02 (pSS26-O) stimulated robust antibody responses against APEC O and S. Typhimurium OPS, with serum titers over 1:800 for both IgG and IgA, thereby providing the complement-mediated bactericidal activity and stronger protection against APEC O and S. Typhimurium infection. Collectively, this study demonstrates a biologically-conjugated polysaccharide vaccine candidate that can enhance homologous protection against APEC O and S. Typhimurium.
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http://dx.doi.org/10.1016/j.vetmic.2021.109012DOI Listing
March 2021

Identification and visualisation of microplastics / nanoplastics by Raman imaging (iii): algorithm to cross-check multi-images.

Water Res 2021 Apr 8;194:116913. Epub 2021 Feb 8.

Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), University of Newcastle, Callaghan NSW 2308, Australia.

We recently developed the Raman mapping image to visualise and identify microplastics / nanoplastics (Fang et al. 2020, Sobhani et al. 2020). However, when the Raman signal is low and weak, the mapping uncertainty from the individual Raman peak intensity increases and may lead to images with false positive or negative features. For real samples, even the Raman signal is high, a low signal-noise ratio still occurs and leads to the mapping uncertainty due to the high spectrum background when: the target plastic is dispersed within another material with interfering Raman peaks; materials are present that exhibit broad Raman peaks; or, materials are present that fluoresce when exposed to the excitation laser. In this study, in order to increase the mapping certainty, we advance the algorithm to combine and merge multi-images that have been simultaneously mapped at the different characteristic peaks from the Raman spectra, akin imaging via different mapping channels simultaneously. These multi-images are merged into one image via algorithms, including colour off-setting to collect signal with a higher ratio of signal-noise, logic-OR to pick up more signal, logic-AND to eliminate noise, and logic-SUBTRACT to remove image background. Specifically, two or more Raman images can act as "parent images", to merge and generate a "daughter image" via a selected algorithm, to a "granddaughter image" via a further selected algorithm, and to an "offspring image" etc. More interestingly, to validate this algorithm approach, we analyse microplastics / nanoplastics that might be generated by a laser printer in our office or home. Depending on the toner and the printer, we might print and generate millions of microplastics and nanoplastics when we print a single A4 document.
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http://dx.doi.org/10.1016/j.watres.2021.116913DOI Listing
April 2021

Comparison of short-channel separation and spatial domain filtering for removal of non-neural components in functional near-infrared spectroscopy signals.

Neurophotonics 2021 Jan 13;8(1):015004. Epub 2021 Feb 13.

Yale School of Medicine, Department of Psychiatry, Brain Function Laboratory, New Haven, Connecticut, United States.

With the increasing popularity of functional near-infrared spectroscopy (fNIRS), the need to determine localization of the source and nature of the signals has grown. We compare strategies for removal of non-neural signals for a finger-thumb tapping task, which shows responses in contralateral motor cortex and a visual checkerboard viewing task that produces activity within the occipital lobe. We compare temporal regression strategies using short-channel separation to a spatial principal component (PC) filter that removes global signals present in all channels. For short-channel temporal regression, we compare non-neural signal removal using first and combined first and second PCs from a broad distribution of short channels to limited distribution on the forehead. Temporal regression of non-neural information from broadly distributed short channels did not differ from forehead-only distribution. Spatial PC filtering provides results similar to short-channel separation using the temporal domain. Utilizing both first and second PCs from short channels removes additional non-neural information. We conclude that short-channel information in the temporal domain and spatial domain regression filtering methods remove similar non-neural components represented in scalp hemodynamics from fNIRS signals and that either technique is sufficient to remove non-neural components.
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http://dx.doi.org/10.1117/1.NPh.8.1.015004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7881368PMC
January 2021

Combination Effect of Three Main Constituents From Inhibits Oxidative Stress in the Mice Following Acute Lung Injury: A Role of MAPK-NF-κB Pathway.

Front Pharmacol 2020 11;11:580064. Epub 2021 Jan 11.

The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.

Caffeoylquinic acids, coumarins and dicaffeoyl derivatives are considered to be three kinds of the most abundant bioactive components in , an anti-inflammatory herb mainly found in Southern Asia. The combined anti-inflammatory effect of three typical constituents C + R + I (chlorogenic acid + rosmarinic acid + isofraxidin) from this plant has been investigated. The result implies that targeting the MAPK-NF-κB pathway would be one of the major mechanisms involved, using LPS stimulated RAW 264.7 cells as model and LPS-induced acute lung injury in mice as model. C + R + I can significantly suppress the levels of nitric oxide (NO), pro-inflammatory cytokines, and inhibit iNOS and COX-2 expression in LPS-treated RAW264.7 macrophage cells. Western blot analysis showed that C + R + I suppressed phosphorylation of NF-κB and MAPK, including phosphorylation of p65-NF-κB, IKB, ERK, JNK and P38. Besides, C + R + I suppressed MPO protein expression, but promoted SOD and HO-1 expression, and the related targets for C, R, and I were also predicted by molecular docking. This indicated that C + R + I could alleviate oxidative stress induced by LPS, which were further verified in the model of mice with acute lung injury through the measurement of corresponding inflammatory mediators and the analysis of immunehistochemistry.
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http://dx.doi.org/10.3389/fphar.2020.580064DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7883675PMC
January 2021

Comparison of Human Social Brain Activity During Eye-Contact With Another Human and a Humanoid Robot.

Front Robot AI 2020 29;7:599581. Epub 2021 Jan 29.

Interdepartmental Neuroscience Program, Yale School of Medicine, New Haven, CT, United States.

Robot design to simulate interpersonal social interaction is an active area of research with applications in therapy and companionship. Neural responses to eye-to-eye contact in humans have recently been employed to determine the neural systems that are active during social interactions. Whether eye-contact with a social robot engages the same neural system remains to be seen. Here, we employ a similar approach to compare human-human and human-robot social interactions. We assume that if human-human and human-robot eye-contact elicit similar neural activity in the human, then the perceptual and cognitive processing is also the same for human and robot. That is, the robot is processed similar to the human. However, if neural effects are different, then perceptual and cognitive processing is assumed to be different. In this study neural activity was compared for human-to-human and human-to-robot conditions using near infrared spectroscopy for neural imaging, and a robot (Maki) with eyes that blink and move right and left. Eye-contact was confirmed by eye-tracking for both conditions. Increased neural activity was observed in human social systems including the right temporal parietal junction and the dorsolateral prefrontal cortex during human-human eye contact but not human-robot eye-contact. This suggests that the type of human-robot eye-contact used here is not sufficient to engage the right temporoparietal junction in the human. This study establishes a foundation for future research into human-robot eye-contact to determine how elements of robot design and behavior impact human social processing within this type of interaction and may offer a method for capturing difficult to quantify components of human-robot interaction, such as social engagement.
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http://dx.doi.org/10.3389/frobt.2020.599581DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7879449PMC
January 2021

Interpersonal Agreement and Disagreement During Face-to-Face Dialogue: An fNIRS Investigation.

Front Hum Neurosci 2020 13;14:606397. Epub 2021 Jan 13.

Faculty of Arts and Humanities, University College London, London, United Kingdom.

Although the neural systems that underlie spoken language are well-known, how they adapt to evolving social cues during natural conversations remains an unanswered question. In this work we investigate the neural correlates of face-to-face conversations between two individuals using functional near infrared spectroscopy (fNIRS) and acoustical analyses of concurrent audio recordings. Nineteen pairs of healthy adults engaged in live discussions on two controversial topics where their opinions were either in agreement or disagreement. Participants were matched according to their opinions on these topics as assessed by questionnaire. Acoustic measures of the recorded speech including the fundamental frequency range, median fundamental frequency, syllable rate, and acoustic energy were elevated during disagreement relative to agreement. Consistent with both the opinion ratings and the acoustic findings, neural activity associated with long-range functional networks, rather than the canonical language areas, was also differentiated by the two conditions. Specifically, the frontoparietal system including bilateral dorsolateral prefrontal cortex, left supramarginal gyrus, angular gyrus, and superior temporal gyrus showed increased activity while talking during disagreement. In contrast, talking during agreement was characterized by increased activity in a social and attention network including right supramarginal gyrus, bilateral frontal eye-fields, and left frontopolar regions. Further, these social and visual attention networks were more synchronous across brains during agreement than disagreement. Rather than localized modulation of the canonical language system, these findings are most consistent with a model of distributed and adaptive language-related processes including cross-brain neural coupling that serves dynamic verbal exchanges.
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http://dx.doi.org/10.3389/fnhum.2020.606397DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7874076PMC
January 2021

Gadolinium-enhanced magnetic resonance versus computed tomography angiography for renal artery stenosis: A systematic review and meta-analysis.

J Formos Med Assoc 2021 Feb 11. Epub 2021 Feb 11.

Radiology Department, Xiangyang NO.1 Hospital, The Affiliated Hospital of Hubei University of Medicine, Xiangyang, 441000, China.

Gadolinium-enhanced magnetic resonance angiography (MRA) and computed tomography angiography (CTA) are commonly used for diagnosing renal arterial stenosis (RAS); however, the diagnostic value is yet controversial. The aim of the study was to evaluate the diagnostic values of both methods. Electronic databases, including PubMed, Embase, and the Cochrane Library, were searched for studies, since inception until October 2017. A total of four articles involving 486 subjects were included in the analysis. The summary of sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the receiver operating characteristic (ROC) (AUC) were 0.70, 0.82, 14.54, 0.29, 63.80, and 0.81 for MRA-based diagnosis of RAS, respectively. The pooled sensitivity, specificity, PLR, NLR, DOR, and AUC for CTA detecting RAS were 0.73, 0.96, 13.04, 0.29, 71.99, and 0.93, respectively. Gadolinium-enhanced MRA and CTA provide a satisfactory diagnostic accuracy, thereby playing a critical role in the diagnosis of RAS.
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http://dx.doi.org/10.1016/j.jfma.2021.01.007DOI Listing
February 2021

Biochemical Characterization and Structural Insight into Interaction and Conformation Mechanisms of Lysine Decarboxylase (SmcadA).

Molecules 2021 Jan 29;26(3). Epub 2021 Jan 29.

The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 LiHu Boulevard, Wuxi 214122, China.

Inducible lysine decarboxylases (LDCs) are essential in various cellular processes of microorganisms and plants, especially under acid stress, which induces the expression of genes encoding LDCs. In this study, a novel LDC (SmcadA) was successfully expressed in , purified and characterized. The protein had an optimal pH of 6 and a temperature of 40 °C and phylogenetic analysis to determine the evolution of SmcadA, which revealed a close relation to sp., among others. The molecular weight of SmcadA was approximately 75 kDa after observation on SDS-PAGE and structural modeling showed the protein as a decamer, comprised of five interlinked dimers. The biocatalytic activity of the purified wild-type SmcadA (WT) was improved through site directed mutations and the results showed that the Arg595Lys mutant had the highest specific activity of 286.55 U/mg, while the Ser512Ala variant and wild-type SmcadA had 215.72 and 179.01 U/mg, respectively. Furthermore, molecular dynamics simulations revealed that interactions through hydrogen bonds between the protein residues and cofactor pyridoxal-5-phosphate (PLP) are vital for biocatalysis. Molecular Dynamics (MD) simulations also indicated that mutations conferred structural changes on protein residues and PLP hence altered the interacting residues with the cofactor, subsequently influencing substrate bioconversion. Moreover, the temperature also induced changes in orientation of cofactor PLP and amino acid residues. This work therefore demonstrates the successful expression and characterization of the purified novel lysine decarboxylase from and provided insight into the mechanism of protein-cofactor interactions, highlighting the role of protein-ligand interactions in altering cofactor and binding site residue conformations, thus contributing to improved biocatalysis.
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http://dx.doi.org/10.3390/molecules26030697DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7866039PMC
January 2021

Characterization of a novel levopimaradiene synthase gene responsible for the biosynthesis of terpene trilactones in .

Plant Signal Behav 2021 Apr 11;16(4):1885906. Epub 2021 Feb 11.

College of Horticulture and Gardening, Yangtze University, Jingzhou, Hubei, China.

Terpene trilactones (TTLs) are the main medicinal compounds of . Levopimaradiene synthase (LPS) is the crucial enzyme that catalyzes TTLs biosynthesis in . In this study, a novel LPS gene (designated as ) was cloned from leaves. The open reading frame of gene was 2520 bp in length, encoding a predicted polypeptide of 840 amino acids. Phylogenetic analysis revealed that the GbLPS2 was highly homologous with reported LPS proteins in other plants. On the basis of the genomic DNA (gDNA) template, a 4308 bp gDNA sequence of and a 913 bp promoter sequence were amplified. -acting elements in promoter analysis indicated that could be regulated by methyl jasmonate (MeJA) and abscisic acid (ABA). Tissue-specific expression analysis revealed that was mainly expressed in roots and ovulate strobilus. MeJA treatment could significantly induce the expression level of and increase the content of TTLs. This study illustrates the structure and the tissue-specific expression pattern of and demonstrates that exogenous hormones regulated the expression of and TTL content in . Our results provide a target gene for the enhancement of TTL content in via genetic engineering.
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http://dx.doi.org/10.1080/15592324.2021.1885906DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7971208PMC
April 2021