Publications by authors named "Xiang Sun"

282 Publications

Functional traits of Fagaceae plants in shady and sunny slopes in karst degraded tiankeng.

Ying Yong Sheng Tai Xue Bao 2021 Jul;32(7):2301-2308

College of Environment and Resources, Fuzhou University, Fuzhou 350116, China.

In the negative terrain habitat of the karst degraded tiankeng, the shady and sunny slopes are dramatically different, which results in substantial variations in plant communities. With the degraded tiankeng Shenxiantang in Zhanyi, Yunnan as an example, we explored the functional traits of Fagaceae plants in the shady and sunny slopes, which would help reveal the value of tiankeng as species diversity conservation pool. The results showed that soil nutrients in the shady slope were more than those in the sunny slope. Leaf area, specific leaf area and leaf dry weight of Faga-ceae plants in the shady slope were significantly larger than those in the sunny slope. Leaf thickness was significantly lower than that in the sunny slope. Dry matter content of leaves was less than that of the sunny slope. The main environmental factors affecting functional traits of Fagaceae plants in the shady slope were soil total potassium concentration and soil moisture, while soil total phosphorus concentration was the key factor in the sunny slope. The extent of variation of leaf functional traits in shady slope was less than that in the sunny slope. Fagaceae plants mainly adapted to the shady slope habitat by changing the leaf dry weight to increase photosynthetic rate and carbon accumulation abi-lity. Sunny slope obtained more resource by keeping smaller specific leaf area and increasing the extent of variation of the leaf area. The succession rate of plant community in the shady slope of the degraded tiankeng Shenxiantang was significantly faster than that in the sunny slope. The dominance of Fagaceae plants gradually decreased in the shady slope, but remained to be the constructive species in the sunny slope.
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http://dx.doi.org/10.13287/j.1001-9332.202107.021DOI Listing
July 2021

Prognostic and Therapeutic Value of Apolipoprotein A and a New Risk Scoring System Based on Apolipoprotein A and Adenosine Deaminase in Chronic Lymphocytic Leukemia.

Front Oncol 2021 1;11:698572. Epub 2021 Jul 1.

Department of Hematology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.

Lipid metabolism is related to lymphomagenesis, and is a novel therapeutic target in some hematologic tumors. Apolipoprotein A (ApoA), the major protein of high-density lipoprotein (HDL), plays a crucial role in lipid transportation and protecting against cardiovascular disease, and takes effect on anti-inflammation and anti-oxidation. It is correlated with the prognosis of some solid tumors. Yet, there is no investigation involving the role of ApoA plays in chronic lymphocytic leukemia (CLL). Our retrospective study focuses on the prognostic value of ApoA in CLL and its therapeutic potential for CLL patients. Herein, ApoA is a favorable independent prognostic factor for both overall survival (OS) and progression-free survival (PFS) of CLL patients. ApoA is negatively associated with β2-microglobulin (β2-MG) and advanced stage, which are poor prognostic factors in CLL. Age, Rai stage, ApoA, and adenosine deaminase (ADA) are included in a new risk scoring system named . It is capable of assessing OS and PFS of CLL patients. Furthermore, cell proliferation assays show that the ApoA-I mimetic L-4F can inhibit the proliferation of CLL cell lines and primary cells. In conclusion, ApoA is of prognostic value in CLL, and is a potential therapy for CLL patients. The may optimize the risk stratification of CLL patients.
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http://dx.doi.org/10.3389/fonc.2021.698572DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8281891PMC
July 2021

Systematic mining of fungal chimeric terpene synthases using an efficient precursor-providing yeast chassis.

Proc Natl Acad Sci U S A 2021 Jul;118(29)

Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, People's Republic of China;

Chimeric terpene synthases, which consist of C-terminal prenyltransferase (PT) and N-terminal class I terpene synthase (TS) domains (termed PTTSs here), is unique to fungi and produces structurally diverse di- and sesterterpenes. Prior to this study, 20 PTTSs had been functionally characterized. Our understanding of the origin and functional evolution of genes is limited. Our systematic search of sequenced fungal genomes among diverse taxa revealed that genes were restricted to Dikarya. Phylogenetic findings indicated different potential models of the origin and evolution of genes. One was that genes originated in the common Dikarya ancestor and then underwent frequent gene loss among various subsequent lineages. To understand their functional evolution, we selected 74 genes for biochemical characterization in an efficient precursor-providing yeast system employing chassis-based, robot-assisted, high-throughput automatic assembly. We found 34 genes that encoded active enzymes and collectively produced 24 di- and sesterterpenes. About half of these di- and sesterterpenes were also the products of the 20 known PTTSs, indicating functional conservation, whereas the PTTS products included the previously unknown sesterterpenes, sesterevisene (1), and sesterorbiculene (2), suggesting that a diversity of PTTS products awaits discovery. Separating functional PTTSs into two monophyletic groups implied that an early gene duplication event occurred during the evolution of the PTTS family followed by functional divergence with the characteristics of distinct cyclization mechanisms.
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http://dx.doi.org/10.1073/pnas.2023247118DOI Listing
July 2021

Three-state harmonic models for photoinduced charge transfer.

J Chem Phys 2021 May;154(17):174105

Division of Arts and Sciences, NYU Shanghai, 1555 Century Avenue, Shanghai 200122, China.

A widely used strategy for simulating the charge transfer between donor and acceptor electronic states in an all-atom anharmonic condensed-phase system is based on invoking linear response theory to describe the system in terms of an effective spin-boson model Hamiltonian. Extending this strategy to photoinduced charge transfer processes requires also taking into consideration the ground electronic state in addition to the excited donor and acceptor electronic states. In this paper, we revisit the problem of describing such nonequilibrium processes in terms of an effective three-state harmonic model. We do so within the framework of nonequilibrium Fermi's golden rule (NE-FGR) in the context of photoinduced charge transfer in the carotenoid-porphyrin-C (CPC) molecular triad dissolved in explicit tetrahydrofuran (THF). To this end, we consider different ways for obtaining a three-state harmonic model from the equilibrium autocorrelation functions of the donor-acceptor, donor-ground, and acceptor-ground energy gaps, as obtained from all-atom molecular dynamics simulations of the CPC/THF system. The quantum-mechanically exact time-dependent NE-FGR rate coefficients for two different charge transfer processes in two different triad conformations are then calculated using the effective three-state model Hamiltonians as well as a hierarchy of more approximate expressions that lead to the instantaneous Marcus theory limit. Our results show that the photoinduced charge transfer in CPC/THF can be described accurately by the effective harmonic three-state models and that nuclear quantum effects are small in this system.
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http://dx.doi.org/10.1063/5.0050289DOI Listing
May 2021

CTRAMER: An open-source software package for correlating interfacial charge transfer rate constants with donor/acceptor geometries in organic photovoltaic materials.

J Chem Phys 2021 Jun;154(21):214108

Department of Physics, University of Houston, 617 Science and Research Building 1, Houston, Texas 77204, USA.

In this paper, we present CTRAMER (Charge-Transfer RAtes from Molecular dynamics, Electronic structure, and Rate theory)-an open-source software package for calculating interfacial charge-transfer (CT) rate constants in organic photovoltaic (OPV) materials based on ab initio calculations and molecular dynamics simulations. The software is based on identifying representative donor/acceptor geometries within interfacial structures obtained from molecular dynamics simulation of donor/acceptor blends and calculating the corresponding Fermi's golden rule CT rate constants within the framework of the linearized-semiclassical approximation. While the methods used are well established, the integration of these state-of-the-art tools originating from different disciplines to study photoinduced CT processes with explicit treatment of the environment, in our opinion, makes this package unique and innovative. The software also provides tools for investigating other observables of interest. After outlining the features and implementation details, the usage and performance of the software are demonstrated with results from an example OPV system.
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http://dx.doi.org/10.1063/5.0050574DOI Listing
June 2021

SIRT6 Promotes Osteogenic Differentiation of Adipose-Derived Mesenchymal Stem Cells Through Antagonizing DNMT1.

Front Cell Dev Biol 2021 22;9:648627. Epub 2021 Jun 22.

Laboratory of Regenerative Medicine, Tianyou Hospital, Wuhan University of Science and Technology, Wuhan, China.

Background: Adipose-derived stem cells (ADSCs) are increasingly used in regenerative medicine because of their potential to differentiate into multiple cell types, including osteogenic lineages. Sirtuin protein 6 (SIRT6) is a nicotinamide adenine dinucleotide (NAD)-dependent deacetylase that plays important roles in cell differentiation. NOTCH signaling has also been reported to involve in osteogenic differentiation. However, the function of SIRT6 in osteogenic differentiation of ADSCs and its relation to the NOTCH signaling pathways are yet to be explored.

Methods: The study with human ADSCs (hADSCs) and experiments with nude mice have been performed. Alkaline phosphatase (ALP) assays and ALP staining were used to detect osteogenic activity. Alizarin Red staining was performed to detect calcium deposition induced by osteogenic differentiation of ADSCs. Western blot, RT-qPCR, luciferase reporter assay, and co-immunoprecipitation assay were applied to explore the relationship between of SIRT6, DNA methyltransferases (DNMTs) and NOTCHs.

Results: SIRT6 promoted ALP activity, enhanced mineralization and upregulated expression of osteogenic-related genes of hADSCs and . Further mechanistic studies showed that SIRT6 deacetylated DNMT1, leading to its unstability at protein level. The decreased expression of DNMT1 prevented the abnormal DNA methylation of NOTCH1 and NOTCH2, resulting in the upregulation of their transcription. SIRT6 overexpression partially suppressed the abnormal DNA methylation of NOTCH1 and NOTCH2 by antagonizing DNMT1, leading to an increased capacity of ADSCs for their osteogenic differentiation.

Conclusion: This study demonstrates that SIRT6 physical interacts with the DNMT1 protein, deacetylating and destabilizing DNMT1 protein, leading to the activation of NOTCH1 and NOTCH2, Which in turn promotes the osteogenic differentiation of ADSCs.
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http://dx.doi.org/10.3389/fcell.2021.648627DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8258422PMC
June 2021

Mechanical behaviors of hydrate-bearing sediment with different cementation spatial distributions at microscales.

iScience 2021 May 16;24(5):102448. Epub 2021 Apr 16.

Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian, 116024, P. R. China.

Unlike the conceptual models, the natural hydrate spatial distribution in sediments is multitype and presents different coalescence degrees. In this study, we present pore-scale triaxial test results for hydrate-bearing sediments with different hydrate spatial distributions for the first time. It shows that the specimen with a more dispersed hydrate distribution yields later and exhibits larger peak strength. Correspondingly, the localized deformation develops more slowly, and the shear band is steeper and thinner. The cementation failure in the specimen with a more dispersed hydrate distribution develops more slowly. However, the changing rate of the pore space characteristic does not seem to be affected by the hydrate spatial distribution. Moreover, the specimen with a more dispersed hydrate distribution has a larger hydrate-sand interfacial area, and further axial loading would increase it rapidly firstly, and then the increasing rate would be slowed down since the cementation structure failure.
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http://dx.doi.org/10.1016/j.isci.2021.102448DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8169796PMC
May 2021

Analysis of epidemiological serosurvey of hepatitis B virus among people under 29 years of age in Jiangsu Province, China.

Hum Vaccin Immunother 2021 Jun 7:1-6. Epub 2021 Jun 7.

Department of Expanded Program on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, Jiangsu, China.

: The purpose of this paper was to analyze the prevalence of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core anti-body (anti-HBc)in1-29 years old living in the most populous eastern province of China,22 years after introduction of hepatitis B vaccine (HepB) vaccination of infants and provide provincial baseline data for developping a better prevention and control plan for hepatitis B virus (HBV)in Jiangsu Province, China: The incidence rates of HBV in Jiangsu province from 2004 to 2014 were obtained from the National Notifiable Disease Reporting System (NNDRS). A stratified cluster random sampling method was used to select 3,002 participants aged 1-29 years across 13 HBV monitoring points throughout the province, which had been classified as either urban or rural. HBV serological markers were measured by Abbott microparticle enzyme immunoassay (MEIA) kits (Abbott Laboratories, Chicago, Illinois).: The incidence of hepatitis B decreased by approximately 71.44% in Jiangsu province between 2004 and 2014. Serological assessments showed that the prevalence of the HBsAg, anti-HBc, and anti-HBsin the 1-29 age group were 1.20%, 5.33%,and 66.89%, respectively. There was a significantly lower prevalence of HepB who were vaccinated than in unvaccinated subjects (0.46% vs 14.93%, < .0001). Among these the ages of 1-29, the coverage rate drops from 97.7% to 56.6% with age,andthe timely rate among people aged 1-14 years was 90.93%.: Since the HepB was integrated into the immunization programme in Jiangsu province,the rate of hepatitis B reported and the prevalence of HBsAg decreased significantly, and the coverage of HepB and the vaccination rate within 24 hours after birth have played an important role in reducing HBV infection.
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http://dx.doi.org/10.1080/21645515.2021.1928461DOI Listing
June 2021

Effect of Ionizing Radiation on the Bacterial and Fungal Endophytes of the Halophytic Plant .

Microorganisms 2021 May 13;9(5). Epub 2021 May 13.

State Key Laboratory of Agrobiotechnology and Key Laboratory of Soil Microbiology, Ministry of Agriculture, College of Biological Sciences, China Agricultural University, Beijing 100193, China.

Endophytic bacteria and fungi colonize plants that grow in various types of terrestrial and aquatic ecosystems. Our study investigates the communities of endophytic bacteria and fungi of halophyte growing in stressed habitats with ionizing radiation. The geochemical factors and radiation (at low, medium, high level and control) both affected the structure of endophytic communities. The bacterial class Actinobacteria and the fungal class Dothideomycetes predominated the endophytic communities of . Aerial tissues of had higher fungal diversity, while roots had higher bacterial diversity. Radiation had no significant effect on the abundance of bacterial classes. Soil pH, total nitrogen, and organic matter showed significant effects on the diversity of root endophytes. Radiation affected bacterial and fungal community structure in roots but not in aerial tissues, and had a strong effect on fungal co-occurrence networks. Overall, the genetic diversity of both endophytic bacteria and fungi was higher in radioactive environments, however negative correlations were found between endophytic bacteria and fungi in the plant. The genetic diversity of both endophytic bacteria and fungi was higher in radioactive environments. Our findings suggest that radiation affects root endophytes, and that the endophytes associated with aerial tissues and roots of follow different mechanisms for community assembly and different paradigms in stress response.
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http://dx.doi.org/10.3390/microorganisms9051050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8152737PMC
May 2021

MicroRNA-99a-5p suppresses cell proliferation, migration, and invasion by targeting isoprenylcysteine carboxylmethyltransferase in oral squamous cell carcinoma.

J Int Med Res 2021 May;49(5):300060520939031

Department of Stomatology, Yan'an Hospital of Traditional Chinese Medicine, Yan'an, Shaanxi Province, China.

Background: MicroRNA (miR)-99a-5p acts as a tumor suppressor in several tumors, including bladder cancer and breast cancer, but its biological function in oral squamous cell carcinoma (OSCC) is poorly understood.

Methods: miR-99a-5p expression was determined in OSCC tissues and cell lines using quantitative reverse transcription polymerase chain reaction (RT-qPCR). Cell proliferation was assessed by the Cell Counting Kit-8 assay and colony formation assay. Wound healing and Transwell assays were used to analyze migration and invasion abilities, respectively, in OSCC cells. The luciferase reporter assay, RT-qPCR, and western blotting were used to determine the relationship between miR-99a-5p and isoprenylcysteine carboxylmethyltransferase (ICMT).

Results: miR-99a-5p expression in OSCC tissues and cell lines was significantly decreased compared with corresponding controls, and was significantly associated with clinical stage and lymph node metastasis in OSCC. Functional assays revealed that miR-99a-5p overexpression significantly inhibited the proliferation, migration, and invasion abilities of CAL-27 and TCA-8113 OSCC cells. miR-99a-5p was found to directly target ICMT, while ICMT restoration reversed the role of miR-99a-5p in OSCC cells.

Conclusions: Our results indicate that miR-99a-5p-mediates the down-regulation of ICMT, which could be used as a novel potential therapeutic target for OSCC treatment.
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http://dx.doi.org/10.1177/0300060520939031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8161884PMC
May 2021

Amygdala dynorphin/κ opioid receptor system modulates depressive-like behavior in mice following chronic social defeat stress.

Acta Pharmacol Sin 2021 May 25. Epub 2021 May 25.

Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.

Major depression disorder is a severe and recurrent neuropsychological disorder characterized by lowered mood and social activity and cognitive impairment. Owing to unclear molecular mechanisms of depression, limited interventions are available in clinic. In this study we investigated the role of dynorphin/κ opioid receptor system in the development of depression. Mice were subjected to chronic social defeat stress for 14 days. Chronic social defeat stress induced significant social avoidance in mice characterized by decreased time duration in the interaction zone and increased time duration in the corner zone. Pre-administration of a κ opioid receptor antagonist norBNI (10 mg/kg, i.p.) could prevent the development of social avoidance induced by chronic social defeat stress. Social avoidance was not observed in κ opioid receptor knockout mice subjected to chronic social defeat stress. We further revealed that social defeat stress activated c-fos and ERK signaling in the amygdala without affecting the NAc, hippocampus and hypothalamus, and ERK activation was blocked by systemic injection of norBNI. Finally, the expression of dynorphin A, the endogenous ligand of κ opioid receptor, was significantly increased in the amygdala following social defeat stress; microinjection of norBNI into the amygdala prevented the development of depressive-like behaviors caused by social defeat stress. The present study demonstrates that upregulated dynorphin/κ opioid receptor system in the amygdala leads to the emergence of depression following chronic social defeat stress, and sheds light on κ opioid receptor antagonists as potential therapeutic agents for the prevention and treatment of depression following chronic stress.
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http://dx.doi.org/10.1038/s41401-021-00677-6DOI Listing
May 2021

Diclazuril Inhibits Biofilm Formation and Hemolysis of .

ACS Infect Dis 2021 06 21;7(6):1690-1701. Epub 2021 May 21.

Department of Infectious Diseases and the Key Lab of Endogenous Infection, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, Guangdong 518052, China.

Biofilm formation and hemolysis induced by are closely related to pathogenicity. However, no drugs exist to inhibit biofilm formation or hemolysis induced by in clinical practice. This study found diclazuril had antibacterial action against with minimum inhibitory concentrations (MICs) at 50 μM for both methicillin-sensitive (MSSA) and methicillin-resistant (MRSA). Diclazuril (at 1/4× or 1/8× MICs) significantly inhibited biofilm formation of under static or flow-based conditions and also inhibited hemolysis induced by . The RNA levels of transcriptional regulatory genes (, , , , , , ), biofilm formation-related genes (, , , , , , , , , , ), and virulence-related genes (, , , , , , , , , , ) of were decreased when treated by diclazuril (at 1/4× MIC) for 4 h. The diclazuril nonsensitive clones of were selected by induction of wildtype strains for about 90 days under the pressure of diclazuril. Mutations in the possible target genes of diclazuril against were detected by whole-genome sequencing. This study indicated that there were three amino acid mutations in the diclazuril nonsensitive clone of , two of which were located in genes with known function (SMC-Scp complex subunit ScpB and glyceraldehyde-3-phosphate dehydrogenase 1, respectively) and one in a gene with unknown function (hypothetical protein). Diclazuril showed a strong inhibition effect on planktonic cells and biofilm formation of with the overexpression of the gene.
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http://dx.doi.org/10.1021/acsinfecdis.1c00030DOI Listing
June 2021

Mutation Is Accompanied by Neutrophil Infiltration and Contributes to Poor Survival in Isocitrate Dehydrogenase Wild-Type Glioma.

Front Cell Dev Biol 2021 30;9:654407. Epub 2021 Apr 30.

Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Functional Neurosurgery, Zhujiang Hospital of Southern Medical University, Guangzhou, China.

Mutation of the telomerase reverse transcriptase (TERT) promoter has been demonstrated as an unfavorable prognostic marker in patients with isocitrate dehydrogenase wild-type (IDHwt) glioma. This study aimed to investigate the immune role of promoter mutation status which could improve prognostic prediction in IDHwt. mutation status, mutation, and 1p-19q codeletion status data were obtained from 614 glioma cases from the Cancer Genome Atlas, and 325 cases from the Chinese Glioma Genome Atlas. The same information was obtained from 49 clinical glioma tissues. mutation is preferentially present in glioblastoma and IDH-wt gliomas and is associated with poor prognosis. Moreover, mutation was associated with infiltration of neutrophils and expression of neutrophil chemokines. which might partially contribute to the poor outcome in IDH-wt glioma. Furthermore, patients with IDH-wt glioma did not harbor increased peripheral neutrophils, implying that the infiltrated neutrophil in the tumor environment might due to cytokine chemotaxis. In this study, we hereby propose that TERT mutation might be a molecular driver of the dysfunctional immune microenvironment in IDH-wt glioma. mutation may be a potential immune therapeutic target for optimizing treatment combinations and patient selection for glioma immunotherapy.
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http://dx.doi.org/10.3389/fcell.2021.654407DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8119999PMC
April 2021

Waning immunity and potential asymptomatic infection in 3-7 years old children who received one dose of measles-mumps-rubella vaccine: A 4-year prospective study.

Vaccine 2021 06 13;39(26):3509-3515. Epub 2021 May 13.

Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing 211166, China; Department of Expanded Programme on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing 210009, China. Electronic address:

Background: Mumps outbreaks in adolescents who received two doses of measles-mumps-rubella vaccine (MMR) during childhood have been reported worldwide. In China, one dose of MMR administered in children aged among 18-24 months has a limited effect on the mumps epidemic. There are limited prospective studies evaluating the mumps immunity profile of children aged 3-7 years who received one dose of MMR. This study aimed to describe mumps immunity profile over a span of 4-years in kindergarten and primary school children.

Methods: An observational, prospective study on one-dose MMR in children aged 3-7 years who underwent blood sample collection in 2015, 2016, and 2018 was conducted from 2015 to 2018. The seropositivity and geometric mean concentration of mumps IgG antibodies over time were analyzed.

Results: A total of 3346 eligible children aged 3-7 years who underwent three rounds of blood sample collection were included. The overall seropositivity (79.6%) in 2015 was significantly higher than those recorded in 2016 (73.1%) and 2018 (71.4%). Approximately 11.6-15.9% of the participants were seropositive for mumps in 2015, and converted to negative in 2016. Meanwhile, 11.1-14.6% of the participants were seropositive for mumps in 2016, and the results converted to negative in 2018. Over 6.1-7.4% of the participants had asymptomatic infection from 2015 to 2016, while 9.0-9.9% of the participants were infected without clinical symptoms from 2016 to 2018.

Conclusions: Kindergarten and primary school children who only received one dose of MMR were at higher risk of developing mumps. Waning immunity, seronegative conversion, and asymptomatic infection coexist in children who received one dose MMR. Determining the optimal age for administering the second dose of MMR in children should be prioritized to improve the control and prevention of mumps in China.
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http://dx.doi.org/10.1016/j.vaccine.2021.05.008DOI Listing
June 2021

Instant Ultrasound-Evoked Precise Nanobubble Explosion and Deep Photodynamic Therapy for Tumors Guided by Molecular Imaging.

ACS Appl Mater Interfaces 2021 May 28;13(18):21097-21107. Epub 2021 Apr 28.

Research Center of Medical Sciences & Department of Radiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China.

Nanobubbles (NBs) have recently gained interest in cancer imaging and therapy due to the fact that nanoparticles with the size range of 1-1000 nm can extravasate into permeable tumor types through the enhanced permeability and retention (EPR) effect. However, the therapeutic study of NBs was only limited to drug delivery or cavitation. Herein, we developed ultrasound-evoked massive NB explosion to strikingly damage the surrounding cancer. The dual-function agent allows synergistic mechanical impact and photodynamic therapy of the tumors and enhances imaging contrast. Moreover, the mechanical explosion improved the light delivery efficiency in biological tissue to promote the effect of photodynamic therapy. Under ultrasound/photoacoustic imaging guidance, we induced on-the-spot bubble explosion and photodynamic therapy of tumors at a depth of centimeters . The mechanical impact of the explosion can enhance delivery of the photosensitizers. Ultrasound explicitly revealed the cancer morphology and exhibited fast NB perfusion. Generated mechanical damage and release of mixture agents demonstrated remarkable synergetic anticancer effects on deep tumors. This finding also offers a new approach and insight into treating cancers.
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http://dx.doi.org/10.1021/acsami.1c05517DOI Listing
May 2021

Stress increases MHC-I expression in dopaminergic neurons and induces autoimmune activation in Parkinson's disease.

Neural Regen Res 2021 Dec;16(12):2521-2527

The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China.

The expression of major histocompatibility complex class I (MHC-I), a key antigen-presenting protein, can be induced in dopaminergic neurons in the substantia nigra, thus indicating its possible involvement in the occurrence and development of Parkinson's disease. However, it remains unclear whether oxidative stress induces Parkinson's disease through the MHC-I pathway. In the present study, polymerase chain reaction and western blot assays were used to determine the expression of MHC-I in 1-methyl-4-phenylpyridinium (MPP)-treated SH-SY5Y cells and a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease mouse model. The findings revealed that MHC-I was expressed in both models. To detect whether the expression of MHC-I was able to trigger the infiltration of cytotoxic T cells, immunofluorescence staining was used to detect cytotoxic cluster of differentiation 8 (CD8) T cell infiltration in the substantia nigra of MPTP-treated mice. The results indicated that the presentation of MHC-I in dopaminergic neurons was indeed accompanied by an increase in the number of CD8 T cells. Moreover, in MPTP-induced Parkinson's disease model mice, the genetic knockdown of endogenous MHC-I, which was caused by injecting specific adenovirus into the substantia nigra, led to a significant reduction in CD8 T cell infiltration and alleviated dopaminergic neuronal death. To further investigate the molecular mechanisms of oxidative stress-induced MHC-I presentation, the expression of PTEN-induced kinase 1 (PINK1) was silenced in MPP-treated SH-SY5Y cells using specific small interfering RNA (siRNA), and there was more presentation of MHC-I in these cells compared with control siRNA-treated cells. Taken together, MPP-/MPTP-induced oxidative stress can trigger MHC-I presentation and autoimmune activation, thus rendering dopaminergic neurons susceptible to immune cells and degeneration. This may be one of the mechanisms of oxidative stress-induced Parkinson's disease, and implies the potential neuroprotective role of PINK1 in oxidative stress-induced MHC-I presentation. All animal experiments were approved by the Southern Medical University Ethics Committee (No. 81802040, approved on February 25, 2018).
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http://dx.doi.org/10.4103/1673-5374.313057DOI Listing
December 2021

Experimental Study of lncRNA RP11-815M8.1 Promoting Osteogenic Differentiation of Human Bone Marrow Mesenchymal Stem Cells.

Biomed Res Int 2021 26;2021:5512370. Epub 2021 Mar 26.

Department of Orthodontics, Stomatological Hospital, Southern Medical University (Guangdong Provincial Stomatological Hospital), Guangzhou, Guangdong 510280, China.

Objective: This study is aimed at investigating the role of long noncoding RNA (lncRNA) RP11-815M8.1 in the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs).

Methods: RT-PCR was used to detect the expression of lncRNA RP11-815M8.1 before and after osteogenic differentiation of hBMSCs. The lncRNA RP11-815M8.1 in hBMSCs was overexpressed or silenced via lentiviral transfection. The transfection efficiency was detected by RT-PCR, and the proliferation of hBMSCs was determined by CCK-8. After 14 days of osteogenic differentiation of transfected hBMSCs, the expression of osteogenic transcription factors (ALP, OCN, OPN, Runx2, and Osterix) was detected by alizarin red staining and RT-PCR. The mRNAs directly regulated by lncRNA RP11-815M8.1 and targeted miRNAs were analyzed according to the positional relationship between lncRNA and mRNA in the genome and miRanda software.

Results: The expression of lncRNA RP11-815M8.1 enhanced with increasing osteogenic differentiation time of hBMSCs. Two days after the transfection of hBMSCs, lncRNA RP11-815M8.1 expression was significantly increased in the overexpression group and significantly decreased in the knockdown group, compared to control cells. The CCK-8 assay showed that overexpression and knockdown of lncRNA RP11-815M8.1 did not affect the proliferation of hBMSCs. After 14 days of differentiation of hBMSCs, stronger alizarin red staining was observed in the overexpression groups, and the expression of osteogenic transcription factors was increased in the overexpression group compared to the control. In the knockdown group, alizarin red staining and the expression of osteogenic transcription factors were decreased. Bioinformatics analysis showed that lncRNA RP11-815M8.1 was directly associated with one mRNA, 27 interacting miRNAs, and 20 miRNA-targeted mRNAs.

Conclusion: The osteogenic differentiation of hBMSCs can be promoted by lncRNA RP11-815M8.1 in vitro.
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http://dx.doi.org/10.1155/2021/5512370DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8019361PMC
May 2021

Pollen PCP-B peptides unlock a stigma peptide-receptor kinase gating mechanism for pollination.

Science 2021 04;372(6538):171-175

School of Life Sciences, East China Normal University, Shanghai, China.

Sexual reproduction in angiosperms relies on precise communications between the pollen and pistil. The molecular mechanisms underlying these communications remain elusive. We established that in , a stigmatic gatekeeper, the ANJEA-FERONIA (ANJ-FER) receptor kinase complex, perceives the RAPID ALKALINIZATION FACTOR peptides RALF23 and RALF33 to induce reactive oxygen species (ROS) production in the stigma papillae, whereas pollination reduces stigmatic ROS, allowing pollen hydration. Upon pollination, the POLLEN COAT PROTEIN B-class peptides (PCP-Bs) compete with RALF23/33 for binding to the ANJ-FER complex, leading to a decline of stigmatic ROS that facilitates pollen hydration. Our results elucidate a molecular gating mechanism in which distinct peptide classes from pollen compete with stigma peptides for interaction with a stigmatic receptor kinase complex, allowing the pollen to hydrate and germinate.
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http://dx.doi.org/10.1126/science.abc6107DOI Listing
April 2021

Lin28 Inhibits the Differentiation from Mouse Embryonic Stem Cells to Glial Lineage Cells through Upregulation of Yap1.

Stem Cells Int 2021 22;2021:6674283. Epub 2021 Feb 22.

Scientific Research Center, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen 518107, China.

The RNA-binding protein Lin28 regulates neurogliogenesis in mammals, independently of the let-7 microRNA. However, the detailed regulatory mechanism remains obscured. Here, we established Lin28a or Lin28b overexpression mouse embryonic stem cells (ESCs) and found that these cells expressed similar levels of the core pluripotent factors, such as Oct4 and Sox2, and increased Yap1 but decreased lineage-specific markers compared to the control ESCs. Further differentiation of these ESCs to neuronal and glial lineage cells revealed that Lin28a/b overexpression did not affect the expression of neuronal marker III-tubulin, but dramatically inhibited the glial lineage markers, such as Gfap and Mbp. Interestingly, overexpression of Yap1 in mouse ESCs phenocopied Lin28a/b overexpression ESCs by showing defect in glial cell differentiation. Inhibition of Yap1/Tead-mediated transcription with verteporfin partially rescued the differentiation defect of Lin28a/b overexpression ESCs. Mechanistically, we demonstrated that Lin28 can directly bind to mRNA, and the induction of Yap1 by Lin28a in mESCs is independent of Let7. Taken together, our results unravel a novel Lin28-Yap1 regulatory axis during mESC to glial lineage cell differentiation, which may shed light on glial cell generation .
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http://dx.doi.org/10.1155/2021/6674283DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7920735PMC
February 2021

Linear-Response and Nonlinear-Response Formulations of the Instantaneous Marcus Theory for Nonequilibrium Photoinduced Charge Transfer.

J Chem Theory Comput 2021 Apr 9;17(4):2065-2079. Epub 2021 Mar 9.

Division of Arts and Sciences, NYU Shanghai, 1555 Century Avenue, Shanghai 200122, China.

Instantaneous Marcus theory (IMT) offers a way for capturing the time-dependent charge transfer (CT) rate coefficient in nonequilibrium photoinduced CT processes, where the system was photoexcited from its equilibrated ground state vertically to the excitonic state, followed by an electronic transition to the CT state. As derived from the linearized semiclassical nonequilibrium Fermi's golden rule (LSC NE-FGR), the original IMT requires expensive all-atom nonequilibrium molecular dynamics (NEMD) simulations. In this work, we propose computationally efficient linear-response and nonlinear-response formulations for IMT rate calculations, which only require equilibrium molecular dynamics simulations. The linear- and nonlinear-response IMT methods were tested to predict the transient behavior in the photoinduced CT dynamics of the carotenoid-porphyrin-C molecular triad solvated in explicit tetrahydrofuran. Our result demonstrated that the nonlinear-response IMT is in excellent agreement with the benchmark NEMD for all cases investigated here, whereas the linear-response IMT predicts the correct trend for all cases but overestimates the transient CT rate in one case involving a significant nonequilibrium relaxation. This mild breakdown of linear-response IMT is due to neglecting the higher-order terms in the exact nonlinear-response IMT. Taking advantage of time translational symmetry, the linear- and nonlinear-response approaches were demonstrated to be able to reduce the computational cost by 80% and 60% compared with NEMD simulations, respectively. Thus, we highly recommend the readily applicable and accurate nonlinear-response IMT approach for simulating nonequilibrium CT processes in complex molecular systems in the condensed phase.
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http://dx.doi.org/10.1021/acs.jctc.0c01250DOI Listing
April 2021

LINC00958 promotes the proliferation of TSCC via miR-211-5p/CENPK axis and activating the JAK/STAT3 signaling pathway.

Cancer Cell Int 2021 Mar 3;21(1):147. Epub 2021 Mar 3.

Department of Oral Surgery, Stomatological Hospital, Southern Medical University, Guangzhou, 510280, China.

Background: Tongue squamous cell carcinoma (TSCC) is one of the most common oral tumors. Recently, long intergenic noncoding RNA 00958 (LINC00958) has been identified as an oncogene in human cancers. Nevertheless, the role of LINC00958 and its downstream mechanisms in TSCC is still unknown.

Methods: The effect of LINC00958 on TSCC cells proliferation and growth were assessed by CCK-8, colony formation, 5-Ethynyl-2'-deoxyuridline (EdU) assay and flow cytometry assays in vitro and tumor xenograft model in vivo. Bioinformatics analysis was used to predict the target of LINC00958 in TSCC, which was verified by RNA immunoprecipitation and luciferase reporter assays.

Results: LINC00958 was increased in TSCC tissues, and patients with high LINC00958 expression had a shorter overall survival. LINC00958 knockdown significantly decreased the growth rate of TSCC cells both in vitro and in vivo. In mechanism, LINC00958 acted as a ceRNA by competitively sponging miR-211-5p. In addition, we identified CENPK as a direct target gene of miR-211-5p, which was higher in TSCC tissues than that in adjacent normal tissues. Up-regulated miR-211-5p or down-regulated CENPK could abolish LINC00958-induced proliferation promotion in TSCC cells. Furthermore, The overexpression of CENPK promoted the expression of oncogenic cell cycle regulators and activated the JAK/STAT3 signaling.

Conclusions: Our findings suggested that LINC00958 is a potential prognostic biomarker in TSCC.
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http://dx.doi.org/10.1186/s12935-021-01808-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7931557PMC
March 2021

Thermochromic aggregation-induced dual phosphorescence via temperature-dependent sp-linked donor-acceptor electronic coupling.

Nat Commun 2021 Mar 1;12(1):1364. Epub 2021 Mar 1.

Hefei National Laboratory for Physical Science at the Microscale, University of Science and Technology of China, Hefei, China.

Aggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient room temperature phosphorescence (RTP) in bulk by restricting molecular motions. Here, we show that by utilizing triphenylamine (TPA) as an electronic donor that connects to an acceptor via an sp linker, six TPA-based AIE-active RTP luminophores were obtained. Distinct dual phosphorescence bands emitting from largely localized donor and acceptor triplet emitting states could be recorded at lowered temperatures; at room temperature, only a merged RTP band is present. Theoretical investigations reveal that the two temperature-dependent phosphorescence bands both originate from local/global minima from the lowest triplet excited state (T). The reported molecular construct serves as an intermediary case between a fully conjugated donor-acceptor system and a donor/acceptor binary mix, which may provide important clues on the design and control of high-freedom molecular systems with complex excited-state dynamics.
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http://dx.doi.org/10.1038/s41467-021-21676-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7921125PMC
March 2021

Linezolid Resistance in Associated With Urinary Tract Infections of Patients in a Tertiary Hospitals in China: Resistance Mechanisms, Virulence, and Risk Factors.

Front Public Health 2021 5;9:570650. Epub 2021 Feb 5.

Department of Infectious Diseases and Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China.

has been commonly considered as one of the major pathogens of the urinary tract infection (UTI) in human host worldwide, whereas the molecular characteristics of clinical isolates from the patients with UTI in China remains seldomly reported. This study aimed to investigate the resistance mechanism, molecular characteristics and risk factors of clinical isolates from patients with UTI in China. A total of 115 non-duplicated clinical isolates from patients with UTI were retrospectively collected in a tertiary hospital in China and their clinical data was further analyzed. The linezolid and tedizolid susceptibility were determined by agar dilution. The resistance genes, including (A)(B)(C)(M)(B), , and MLST-based housekeeping genes were investigated by PCR. In 115 non-duplicated clinical isolates from the patients with UTI in this hospital setting, the frequency of linezolid or tedizolid-resistant/intermediate isolates were 22.61 and 13.04%, respectively, and the frequency of linezolid-resistant/intermediate clinical isolates carrying with (A) were 86%. Among the five linezolid-resistant strains found in this study, three positive isolates and the other two linezolid-resistant strains were G2576U genetic mutations in the V domain of the 23S rRNA genes. The ST clonality analysis indicated that 31.42% (11/35) of ST16 UTI isolates were not susceptible to linezolid. Moreover, the univariable analysis indicated that the high risk factors of linezolid-resistant/intermediate infections involved the indwelling catheter, trachea cannula catheter and the carriage of (A) or . Furthermore, the indwelling catheter and trachea cannula catheter were demonstrated as the independent predictors of linezolid-resistant/intermediate strains in patients with UTI by multivariable analysis. Linezolid-resistant/intermediate associated with urinary tract infections of patients in this hospital setting from China might be explained by the high carriage frequency of genes and moreover, indwelling catheter and trachea cannula should be considered as the independent predictors of linezolid-resistant/intermediate infections. The transmission mechanism of linezolid-resistant/intermediate in this hospital setting should be further studied.
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http://dx.doi.org/10.3389/fpubh.2021.570650DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7893085PMC
May 2021

Progress of Exsolved Metal Nanoparticles on Oxides as High Performance (Electro)Catalysts for the Conversion of Small Molecules.

Small 2021 Mar 3;17(10):e2005383. Epub 2021 Feb 3.

Institute of Electrochemical & Energy Technology, Department of Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.

Utilizing electricity and heat from renewable energy to convert small molecules into value-added chemicals through electro/thermal catalytic processes has enormous socioeconomic and environmental benefits. However, the lack of catalysts with high activity, good long-term stability, and low cost strongly inhibits the practical implementation of these processes. Oxides with exsolved metal nanoparticles have recently been emerging as promising catalysts with outstanding activity and stability for the conversion of small molecules, which provides new possibilities for application of the processes. In this review, it starts with an introduction on the mechanism of exsolution, discussing representative exsolution materials, the impacts of intrinsic material properties and external environmental conditions on the exsolution behavior, and the driving forces for exsolution. The performances of exsolution materials in various reactions, such as alkane reforming reaction, carbon monoxide oxidation, carbon dioxide utilization, high temperature steam electrolysis, and low temperature electrocatalysis, are then summarized. Finally, the challenges and future perspectives for the development of exsolution materials as high-performance catalysts are discussed.
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http://dx.doi.org/10.1002/smll.202005383DOI Listing
March 2021

The Antibacterial and Antibiofilm Activity of Telithromycin Against spp. Isolated From Patients in China.

Front Microbiol 2020 14;11:616797. Epub 2021 Jan 14.

Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infections, Shenzhen Nanshan People's Hospital, Shenzhen University of School Medicine, Shenzhen, China.

Telithromycin has been reported to possess robust antibacterial activity against many species of gram-positive bacteria, and telithromycin is also effective against biofilms. However, the antimicrobial susceptibility of telithromycin against clinical enterococci isolates in China is rarely reported and the impacts of telithromycin on the biofilm formation and eradication of enterococci remain elusive. Therefore, this study aimed to explore the inhibitory effects of telithromycin on planktonic cells and biofilms of strains. A total of 280 and 122 isolates were collected from individual inpatients in China. The 50% minimum inhibitory concentration (MIC) values of telithromycin against the and strains carrying erythromycin-resistant methylase () genes such as the , , or , were 2 and 4 μg/mL, respectively. In addition, these isolates were typed using multilocus sequence typing (MLST) based on housekeeping genes. The predominant sequence types (STs) of were ST16, ST30, and ST179, and the main STs of isolates were ST18, ST78, and ST80. Among these major STs, 87.1% (135/158) of and 80.4% (41/51) of carried genes. Furthermore, at the subinhibitory concentrations (1/4 and 1/8 × MIC) of telithromycin, the biofilm formation of 16 isolates were inhibited by approximately 35%. Moreover, treatment with 8 × MIC of telithromycin or ampicillin led to an almost 40% reduction in the established biofilms of isolates, whereas vancomycin or linezolid with 8 × MIC had minimal effects. The combination of telithromycin and ampicillin resulted in an almost 70% reduction in the established biofilms of . In conclusion, these results revealed that telithromycin significantly decreased the planktonic cells of both and . In addition, the data further demonstrated that telithromycin has the robust ability to inhibit biofilms and the combination of telithromycin and ampicillin improved antibiofilm activity. These antibacterial and antibiofilm activities suggest that telithromycin could be a potential candidate for the treatment of enterococcal infections.
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http://dx.doi.org/10.3389/fmicb.2020.616797DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7841295PMC
January 2021

Decarboxylative Polyfluoroarylation of Alkylcarboxylic Acids.

Angew Chem Int Ed Engl 2021 05 30;60(19):10557-10562. Epub 2021 Mar 30.

Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany.

Polyfluoroarenes are useful building blocks in several areas such as drug discovery, materials, and crop protection. Herein, we report the first polyfluoroarylation of aliphatic carboxylic acids via photoredox decarboxylation. The method proceeds with broad substrate scope and high functional group tolerance. Moreover, small complex molecules such as natural products and drugs can be modified by late-stage modification.
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http://dx.doi.org/10.1002/anie.202015596DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8252513PMC
May 2021

Pantothenate mediates the coordination of whitefly and symbiont fitness.

ISME J 2021 06 11;15(6):1655-1667. Epub 2021 Jan 11.

Liaoning Key Laboratory of Economic and Applied Entomology, College of Plant Protection, Shenyang Agricultural University, Shenyang, 110866, China.

Intracellular symbionts in insects often have reduced genomes. Host acquisition of genes from bacteria is an important adaptation that supports symbionts. However, the function of horizontally transferred genes in insect symbiosis remains largely unclear. The primary symbiont Portiera housed in bacteriocytes lacks pantothenate synthesis genes: panB and panC, which is presumably complemented by a fused gene panB-panC (hereafter panBC) horizontally transferred from bacteria in Bemisia tabaci MEAM1. We found panBC in many laboratory cultures, and species of B. tabaci shares a common evolutionary origin. We demonstrated that complementation with whitefly panBC rescued E. coli pantothenate gene knockout mutants. Portiera elimination decreased the pantothenate level and PanBC abundance in bacteriocytes, and reduced whitefly survival and fecundity. Silencing PanBC decreased the Portiera titer, reduced the pantothenate level, and decreased whitefly survival and fecundity. Supplementation with pantothenate restored the symbiont titer, PanBC level, and fitness of RNAi whiteflies. These data suggest that pantothenate synthesis requires cooperation and coordination of whitefly PanBC expression and Portiera. This host-symbiont co-regulation was mediated by the pantothenate level. Our findings demonstrated that pantothenate production, by the cooperation of a horizontally acquired, fused bacteria gene and Portiera, facilitates the coordination of whitefly and symbiont fitness. Thus, this study extends our understanding on the basis of complex host-symbiont interactions.
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http://dx.doi.org/10.1038/s41396-020-00877-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8163847PMC
June 2021

Proteomic analysis of hydrolytic proteases in excretory/secretory proteins from Trichinella spiralis intestinal infective larvae using zymography combined with shotgun LC-MS/MS approach.

Acta Trop 2021 Apr 7;216:105825. Epub 2021 Jan 7.

Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou 450052, China. Electronic address:

The critical step of Trichinella spiralis infection is that the muscle larvae (ML) are activated to intestinal infective larvae (IIL) which invade the intestinal columnar epithelium to further develop. The IIL excretory/secretory (ES) proteins play an important role in host-parasite interaction. Proteolytic enzymes are able to mediate the tissue invasion, thereby increasing the susceptibility of parasites to their hosts. The aim of the current study was to screen and identify the natural active proteases in T. spiralis IIL ES proteins using Western blot and gel zymography combined with liquid chromatography tandem mass spectrometry (LC-MS/MS). The T. spiralis ML and IIL ES proteins were collected from the in vitro cultures and their enzymatic acitvities were examined by gelatin zymography and azocasein degradation. The protease activities were partially inhibited by PMSF, E-64 and EDTA. Three protein bands (45, 118 and 165 kDa) of T. spiralis IIL ES proteins were identified by shotgun LC-MS/MS because they have hydrolytic activity to gelatin compared to the ML ES proteins. Total of 30 T. spiralis proteins were identified and they are mainly serine proteinases (19), but also metalloproteinases (7) and cysteine proteinases (3). The qPCR results indicated that transcription levels of four T. spiralis protease genes (two serine proteases, a cathepsin B-like cysteine proteinase and a zinc metalloproteinase) at IIL stage were obviously higher than at the ML stage. These proteolytic enzymes are directly exposed to the host intestinal milieu and they may mediate the worm invasion of enteral epithelium and escaping from the host's immune responses. The results provide the new insights into understanding of the interaction of T. spiralis with host and the invasion mechanism.
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http://dx.doi.org/10.1016/j.actatropica.2021.105825DOI Listing
April 2021

An evolutionary systematic framework to quantify short-term and long-term watershed ecological compensation standard and amount for promoting sustainability of livestock industry based on cost-benefit analysis, linear programming, WTA and WTP method.

Environ Sci Pollut Res Int 2021 Apr 6;28(14):18004-18020. Epub 2021 Jan 6.

College of Resources, Environment and Materials, Guangxi University, Nanning, 530004, People's Republic of China.

In order to achieve at better water quality of a given trans-boundary river mainly contributed by high-intensive and spatially dispersed pig farming at upstream area, an effective ecological compensation system is in urgent need. In this study, an evolutionary bottom-up framework of ecological compensation system was proposed to analyze the tradeoffs of behavior among the pig farmers, government of upstream area, and government of downstream area. Shutting down pig farms, upgrading traditional piggeries to elevated bed piggeries, and adopting centralized facilities for disposing wastes from small-scale pig farms are three effective measures to control pollution from pig farming and were considered into this study. The combined use of cost-benefit analysis, linear programming, willingness to accept and willingness to pay method, and its application to a typical case of Jiuzhou River, China, showed good performance to quantify short-term and long-term watershed ecological compensation standard and amount for promoting sustainability of livestock industry. Besides, we also proposed a framework of long-term reward and punishment compensation mechanism binding upon both sides for maintaining good water quality. The proposed systematic and feasible framework of methodology has important theoretical and application significance for other similar related researches and enriched the field in paying for good water quality.
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http://dx.doi.org/10.1007/s11356-020-11769-xDOI Listing
April 2021

Activity of the Novel Tetracyclines, Tigecycline, Eravacycline, and Omadacycline, Against .

Ann Lab Med 2021 May;41(3):293-301

Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infection, Shenzhen Nanshan People's Hospital, Shenzhen University of School Medicine, Shenzhen, China.

Background: Tigecycline, eravacycline, and omadacycline are recently developed tetracyclines. Susceptibility of microbes to these tetracyclines and their molecular mechanisms have not been well elucidated. We investigated the susceptibility of to tigecycline, eravacycline, and omadacycline and its resistance mechanisms against these tetracyclines.

Methods: A total of 207 non-duplicate isolates were collected from different inpatients. The minimum inhibitory concentrations (MICs) of the tetracyclines were determined by broth microdilution. Tigecycline-, eravacycline-, or omadacycline-resistant isolates were induced under pressure. The tet genes and mutations in the 16S rRNA was detected by PCR and sequencing.

Results: Eravacycline had a lower MIC (0.06 mg/L) than tigecycline (0.125 mg/L) or omadacycline (0.125 mg/L) against isolates. We found that 136 isolates (65.7%) had the gene, and 15 (7.2%) isolates were positive for however, their presence was not correlated with high tigecycline, eravacycline, or omadacycline (≥1 mg/L) MICs. Compared with the initial MIC after 160 days of induction, the MICs of tigecycline or eravacycline against three isolates increased ≥eight-fold, while those of omadacycline against two isolates increased 64-fold. Mutations in the 16S rRNA genes (C1036T and/or G460A) were observed in omadacycline-induced resistant isolates, and increased RR (the genes encoding 16SrRNA (four copies, RR1-RR4) copy number of 16S rRNA genes with mutations was associated with increased resistance to omadacycline.

Conclusions: Tigecycline, eravacycline, and omadacycline exhibited robust antimicrobial effects against . Mutations in the 16S rRNA genes contributed to omadacycline resistance in .
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http://dx.doi.org/10.3343/alm.2021.41.3.293DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7748099PMC
May 2021
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