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1.
PLoS Pathog ; 20(1): e1011967, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38271479

ABSTRACT

Given the serious neurological complications and deaths associated with enterovirus 71 (EV71) infection, there is an urgent need to develop effective antivirals against this viral infection. In this study, we demonstrated that two Cathelicidin-derived peptides, LL-18 and FF-18 were more potent against EV71 infection than the parent peptide LL-37, which is the mature and processed form of Cathelicidin. These peptides could directly bind to the EV71 virus particles, but not to coxsackievirus, indicative of their high specificity. The binding of peptides with the virus surface occupied the viral canyon region in a way that could block virus-receptor interactions and inhibit viral uncoating. In addition, these peptide analogues could also relieve the deleterious effect of EV71 infection in vivo. Therefore, Cathelicidin-derived peptides might be excellent candidates for further development of antivirals to treat EV71 infection.


Subject(s)
Enterovirus A, Human , Enterovirus Infections , Enterovirus , Humans , Cathelicidins/pharmacology , Virus Internalization , Antiviral Agents/metabolism
2.
J Virol ; 98(2): e0174923, 2024 Feb 20.
Article in English | MEDLINE | ID: mdl-38189249

ABSTRACT

Enterovirus 71 (EV71) is one of the major pathogens causing hand, foot, and mouth disease in children under 5 years old, which can result in severe neurological complications and even death. Due to limited treatments for EV71 infection, the identification of novel host factors and elucidation of mechanisms involved will help to counter this viral infection. N-terminal acetyltransferase 6 (NAT6) was identified as an essential host factor for EV71 infection with genome-wide CRISPR/Cas9 screening. NAT6 facilitates EV71 viral replication depending on its acetyltransferase activity but has little effect on viral release. In addition, NAT6 is also required for Echovirus 7 and coxsackievirus B5 infection, suggesting it might be a pan-enterovirus host factor. We further demonstrated that NAT6 is required for Golgi integrity and viral replication organelle (RO) biogenesis. NAT6 knockout significantly inhibited phosphatidylinositol 4-kinase IIIß (PI4KB) expression and PI4P production, both of which are key host factors for enterovirus infection and RO biogenesis. Further mechanism studies confirmed that NAT6 formed a complex with its substrate actin and one of the PI4KB recruiters-acyl-coenzyme A binding domain containing 3 (ACBD3). Through modulating actin dynamics, NAT6 maintained the integrity of the Golgi and the stability of ACBD3, thereby enhancing EV71 infection. Collectively, these results uncovered a novel mechanism of N-acetyltransferase supporting EV71 infection.IMPORTANCEEnterovirus 71 (EV71) is an important pathogen for children under the age of five, and currently, no effective treatment is available. Elucidating the mechanism of novel host factors supporting viral infection will reveal potential antiviral targets and aid antiviral development. Here, we demonstrated that a novel N-acetyltransferase, NAT6, is an essential host factor for EV71 replication. NAT6 could promote viral replication organelle (RO) formation to enhance viral replication. The formation of enterovirus ROs requires numerous host factors, including acyl-coenzyme A binding domain containing 3 (ACBD3) and phosphatidylinositol 4-kinase IIIß (PI4KB). NAT6 could stabilize the PI4KB recruiter, ACBD3, by inhibiting the autophagy degradation pathway. This study provides a fresh insight into the relationship between N-acetyltransferase and viral infection.


Subject(s)
Enterovirus A, Human , Enterovirus Infections , N-Terminal Acetyltransferases , Phosphotransferases (Alcohol Group Acceptor) , Child , Child, Preschool , Humans , 1-Phosphatidylinositol 4-Kinase/metabolism , Actins/metabolism , Adaptor Proteins, Signal Transducing/metabolism , Antiviral Agents , Coenzyme A/metabolism , Coxsackievirus Infections , Enterovirus A, Human/physiology , Enterovirus Infections/metabolism , Enterovirus Infections/virology , Membrane Proteins/metabolism , N-Terminal Acetyltransferases/metabolism , Organelle Biogenesis , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Virus Replication/physiology
3.
Plant Cell ; 34(5): 1890-1911, 2022 04 26.
Article in English | MEDLINE | ID: mdl-35166333

ABSTRACT

The unique morphology of grass stomata enables rapid responses to environmental changes. Deciphering the basis for these responses is critical for improving food security. We have developed a planta platform of single-nucleus RNA-sequencing by combined fluorescence-activated nuclei flow sorting, and used it to identify cell types in mature and developing stomata from 33,098 nuclei of the maize epidermis-enriched tissues. Guard cells (GCs) and subsidiary cells (SCs) displayed differential expression of genes, besides those encoding transporters, involved in the abscisic acid, CO2, Ca2+, starch metabolism, and blue light signaling pathways, implicating coordinated signal integration in speedy stomatal responses, and of genes affecting cell wall plasticity, implying a more sophisticated relationship between GCs and SCs in stomatal development and dumbbell-shaped guard cell formation. The trajectory of stomatal development identified in young tissues, and by comparison to the bulk RNA-seq data of the MUTE defective mutant in stomatal development, confirmed known features, and shed light on key participants in stomatal development. Our study provides a valuable, comprehensive, and fundamental foundation for further insights into grass stomatal function.


Subject(s)
Plant Stomata , Zea mays , Humans , Plant Leaves/metabolism , Plant Stomata/metabolism , Poaceae/genetics , Transcriptome/genetics , Zea mays/genetics
4.
Proc Natl Acad Sci U S A ; 119(9)2022 03 01.
Article in English | MEDLINE | ID: mdl-35193978

ABSTRACT

The architectural protein histone-like protein from Escherichia coli strain U93 (HU) is the most abundant bacterial DNA binding protein and highly conserved among bacteria and Apicomplexan parasites. It not only binds to double-stranded DNA (dsDNA) to maintain DNA stability but also, interacts with RNAs to regulate transcription and translation. Importantly, HU is essential to cell viability for many bacteria; hence, it is an important antibiotic target. Here, we report that Gp46 from bacteriophage SPO1 of Bacillus subtilis is an HU inhibitor whose expression prevents nucleoid segregation and causes filamentous morphology and growth defects in bacteria. We determined the solution structure of Gp46 and revealed a striking negatively charged surface. An NMR-derived structural model for the Gp46-HU complex shows that Gp46 occupies the DNA binding motif of the HU and therefore, occludes DNA binding, revealing a distinct strategy for HU inhibition. We identified the key residues responsible for the interaction that are conserved among HUs of bacteria and Apicomplexans, including clinically significant Mycobacterium tuberculosis, Acinetobacter baumannii, and Plasmodium falciparum, and confirm that Gp46 can also interact with these HUs. Our findings provide detailed insight into a mode of HU inhibition that provides a useful foundation for the development of antibacteria and antimalaria drugs.


Subject(s)
Bacterial Proteins/antagonists & inhibitors , Bacteriophages/metabolism , DNA-Binding Proteins/antagonists & inhibitors , Glycoproteins/metabolism , Viral Proteins/metabolism , Bacterial Proteins/metabolism , DNA/metabolism , DNA-Binding Proteins/metabolism , Protein Binding
5.
J Am Chem Soc ; 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38936812

ABSTRACT

Direct site-selective and enantioselective oxyfunctionalization of C(sp3)-H bonds to form alcohols with a general scope, with predictable selectivities, and in preparatively useful yields represents a paradigm shift in the standard logic of synthetic organic chemistry. However, the knowledge of either enzymatic or nonenzymatic asymmetric hydroxylation of tertiary C-H bonds for enantioenriched tertiary alcohol synthesis is sorely lacking. Here, we report a practical manganese-catalyzed enantio-differentiating hydroxylation of tertiary propargylic C-H bonds in acyclic systems, producing a wide range of structurally diverse enantioenriched tertiary propargyl alcohols in high efficiency with extremely efficient chemo- and enantio-discrimination. Other features include the use of C-H substrates as the limiting reagent, noteworthy functional group compatibility, great synthetic utilities, and scalability. The findings serve as a blueprint for the development of metal-catalyzed asymmetric oxidation of challenging substrates.

6.
Analyst ; 149(8): 2420-2427, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38488061

ABSTRACT

Antimicrobial resistance has become a major global health threat due to the misuse and overuse of antibiotics. Rapid, affordable, and high-efficiency antimicrobial susceptibility testing (AST) is among the effective means to solve this problem. Herein, we developed a capillary-based centrifugal indicator (CBCI) equipped with an in situ culture of pathogenic bacteria for fast AST. The bacterial incubation and growth were performed by macro-incubation, which seamlessly integrated the capillary indicator. Through simple centrifugation, all the bacterial cells were confined at the nanoliter-level capillary column. The packed capillary column height could linearly reflect the bacterial count, and the minimum inhibitory concentration (MIC) was determined based on the difference in the column height between the drug-added groups and the control group. The AST results could easily be determined by the naked eye or smartphone imaging. Thus, the CBCI realized the combination of macro-bacterial incubation and early micro assessment, which accelerated the phenotypic AST without complex microscopic counting or fluorescent labelling. The whole operation process was simple and easy to use. AST results could be determined for E. coli ATCC strains within 3.5 h, and the output results for clinical samples were consistent with the hospital reports. We expect this AST platform to become a useful tool in limiting antimicrobial resistance, especially in remote/resource-limited areas or in underdeveloped countries.


Subject(s)
Anti-Bacterial Agents , Escherichia coli , Anti-Bacterial Agents/pharmacology , Microbial Sensitivity Tests , Bacteria
7.
Cell Biol Toxicol ; 40(1): 26, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38691186

ABSTRACT

Copper ionophore NSC319726 has attracted researchers' attention in treating diseases, particularly cancers. However, its potential effects on male reproduction during medication are unclear. This study aimed to determine whether NSC319726 exposure affected the male reproductive system. The reproductive toxicity of NSC319726 was evaluated in male mice following a continuous exposure period of 5 weeks. The result showed that NSC319726 exposure caused testis index reduction, spermatogenesis dysfunction, and architectural damage in the testis and epididymis. The exposure interfered with spermatogonia proliferation, meiosis initiation, sperm count, and sperm morphology. The exposure also disturbed androgen synthesis and blood testis barrier integrity. NSC319726 treatment could elevate the copper ions in the testis to induce cuproptosis in the testis. Copper chelator rescued the elevated copper ions in the testis and partly restored the spermatogenesis dysfunction caused by NSC319726. NSC319726 treatment also decreased the level of retinol dehydrogenase 10 (RDH10), thereby inhibiting the conversion of retinol to retinoic acid, causing the inability to initiate meiosis. Retinoic acid treatment could rescue the meiotic initiation and spermatogenesis while not affecting the intracellular copper ion levels. The study provided an insight into the bio-safety of NSC319726. Retinoic acid could be a potential therapy for spermatogenesis impairment in patients undergoing treatment with NSC319726.


Subject(s)
Copper , Spermatogenesis , Testis , Tretinoin , Male , Animals , Spermatogenesis/drug effects , Tretinoin/pharmacology , Copper/toxicity , Mice , Testis/drug effects , Testis/metabolism , Testis/pathology , Spermatogonia/drug effects , Spermatogonia/metabolism , Spermatozoa/drug effects , Spermatozoa/metabolism , Meiosis/drug effects , Epididymis/drug effects , Epididymis/metabolism , Epididymis/pathology
8.
Phytopathology ; 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38829930

ABSTRACT

Leaf rust is a widespread foliar wheat disease causing substantial yield losses worldwide. Slow-rusting is "adult plant" resistance that significantly slows epidemic development and thereby reduces yield loss. Wheat accession CI 13227 was previously characterized as having slow-rusting resistance. To validate the quantitative trait loci (QTL) and develop diagnostic markers for slow rusting resistance in CI 13227, a new population of recombinant inbred lines (RILs) of CI 13227 × Everest was evaluated for latent period (LP), final severity (FS), area under disease progress curve (AUDPC), and infection type (IT) in greenhouses and genotyped using genotyping-by-sequencing (GBS). Four QTL were identified on chromosome arms 2BL, 2DS, 3BS, and 7BL, explaining 6.82 to 28.45% of the phenotypic variance for these traits. Seven kompetitive allele specific polymorphism (KASP) markers previously reported to be linked to the QTL in two other CI 13227 populations were validated. In addition, the previously reported QLr.hwwg-7AL was remapped to 2BL (renamed QLr.hwwg-2BL) after adding new markers in this study. Phenotypic data showed that the RILs harboring two or three of the QTL had a significantly longer LP. QLr.hwwg-2DS on 2DS showed a major effect on all rust resistance traits and was finely mapped to a 2.7 Mb interval by two newly developed flanking markers from exome capture. Three disease-resistance genes and two transporter genes were identified as the putative candidates for QLr.hwwg-2DS. The validated QTL can be used as slow rusting resistance resources and the markers developed in this study will be useful for marker-assisted selection.

9.
Article in English | MEDLINE | ID: mdl-38401088

ABSTRACT

Background: Lumbar spondylolysis (LS) poses a potential threat, and there is a need to evaluate and compare the effectiveness of direct pars repair techniques. Objective: To assess and compare the clinical and radiographic outcomes of direct pars repair techniques using the pedicle screw hook system (PSHS) and the pedicle screw rod system (PSRS) in young symptomatic patients with lumbar spondylolysis. Methods: A retrospective study was conducted to compare clinical and radiological data in young symptomatic LS patients after surgery. Records of 45 post-surgery LS patients with a minimum 24-month follow-up (January 2014 to June 2019) were reviewed. A total of 26 patients underwent PSHS, and 19 had PSRS. Treatment outcomes were analyzed using the visual analog pain scale (VAS), Oswestry disability index (ODI), MacNab criteria, lumbar fusion status, and Pfirrmann grading standards. Patient baseline characteristics were also compared between the two groups. Results: No disc degeneration was observed in either PSHS or PSRS groups at 24 months postoperatively, according to the Pfirrmann grading scale. The PSRS group outperformed the PSHS group in operative time, intraoperative blood loss, postoperative drainage, length of hospital stays, ODI, VAS values at 3 months postoperatively, and fusion status at 6 months postoperatively. No notable differences were observed in other parameters during the 24-month follow-up period, and no significant surgical complications were recorded. Conclusions: Direct pars repair techniques using PSHS and PSRS yielded satisfactory clinical and radiographic results in young patients with symptomatic LS. PSRS, compared to PSHS, demonstrated greater effectiveness in young individuals with LS and promoted early recovery.

10.
Public Health ; 228: 186-193, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38387115

ABSTRACT

OBJECTIVES: China has the largest number of hepatitis C virus (HCV) infection in the world, but current levels of diagnosis and treatment are low. The objective of this study was to assess the cost-effectiveness of various universal HCV screening and treatment strategies in China and inform decisions on health policy. STUDY DESIGN: A cost-effectiveness analytical study. METHODS: We developed a Markov model to investigate cost-effectiveness of different HCV screening and treatment strategies in China. We simulated several screening scenarios for Chinese people aged 18-70 years. We estimated incremental cost-effectiveness ratios (ICERs) of different intervention scenarios compared with status quo. RESULTS: Expanded HCV screening and treatment strategy with prioritisation for high-risk groups (Scenario S5) was the most cost-effective strategy (ICER: USD $11,667.71/quality-adjusted life-year [QALY] gained), which resulted in great reduction in HCV-related diseases and deaths, with a 67.11% reduction in cases of chronic HCV. Universal HCV screening and treatment implementation remains a cost-effective strategy when delayed until 2025 (ICER: USD $17,093.69/QALY), yet the delayed strategy is less effective in reducing HCV-related deaths. CONCLUSIONS: Expanded HCV screening and treatment strategy with prioritisation for high-risk groups is the most cost-effective strategy and has lead to a significant reduction in both HCV morbidity and mortality in China, which would essentially eliminate HCV as a public threat.


Subject(s)
Hepatitis C, Chronic , Mass Screening , Humans , Antiviral Agents/therapeutic use , China/epidemiology , Cost-Benefit Analysis , East Asian People , Hepacivirus , Hepatitis C, Chronic/diagnosis , Hepatitis C, Chronic/drug therapy , Hepatitis C, Chronic/epidemiology , Quality-Adjusted Life Years , Adolescent , Young Adult , Adult , Middle Aged , Aged
11.
J Virol ; 96(6): e0011922, 2022 03 23.
Article in English | MEDLINE | ID: mdl-35170979

ABSTRACT

Enterovirus 71 (EV71) is deemed a reemergent pathogen, with recent outbreaks worldwide. EV71 infection causes hand, foot, and mouth disease (HFMD) and has been associated with severe cardiac and central nervous system complications and even death. Viruses need host factors to complete their life cycle; therefore, the identification of the host factors for EV71 infection is pivotal to new antiviral research. Emerging evidence has highlighted the importance of protein acetylation during infection by various human viruses. The endoplasmic reticulum (ER), as the prominent organelle of EV71 replication, also has a unique acetylation regulation mechanism. However, the pathogenesis of EV71 and its relationship with the ER-based acetylation machinery are not fully understood. In this study, we demonstrated for the first time that the ER-resident acetyltransferase N-acetyltransferase 8 (NAT8) is a host factor for EV71 infection. Inhibiting NAT8 with CRISPR or a small compound significantly suppressed EV71 infection in SK-N-SH cells. NAT8 promoted EV71 replication in an acetyltransferase-activity-dependent manner. Additionally, we found that NAT8 facilitates EV71 infection by interacting with EV71 2B, 3AB, and 3C proteins and increasing the stability of these proteins. These results uncovered a novel function of NAT8 and elucidated a new mechanism underlying the regulation of EV71 replication. IMPORTANCE EV71 is one of the most common pathogens causing HFMD in young children, and some patients experience severe or fatal neurological consequences. To ensure efficient replication, the virus must hijack multiple host factors for its own benefit. Here, we show that the ER-resident acetyltransferase NAT8 is a host factor for EV71 infection. EV71 fails to complete its infection in various cells in the absence of NAT8. We further show that NAT8 benefits EV71 replication in an acetyltransferase-activity-dependent manner. Finally, we show that NAT8 facilitates EV71 infection by interacting with EV71 2B, 3AB, and 3C proteins and increasing the stability of these proteins. These results uncovered a novel function of NAT8 in EV71 infection and elucidated a new mechanism underlying the regulation of EV71 replication.


Subject(s)
Acetyltransferases , Enterovirus A, Human , Enterovirus Infections , Viral Nonstructural Proteins , Virus Replication , Acetyltransferases/metabolism , Enterovirus A, Human/physiology , Humans , Viral Nonstructural Proteins/metabolism
12.
J Med Virol ; 95(1): e28212, 2023 01.
Article in English | MEDLINE | ID: mdl-36224449

ABSTRACT

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has posed a serious threat to public health and has quickly become a global concern. The infection of SARS-CoV-2 begins with the binding of its spike protein to the receptor-angiotensin-converting enzyme 2 (ACE2), which, after a series of conformation changes, results in the fusion of viral-cell membranes and the release of the viral RNA genome into the cytoplasm. In addition, infected host cells can express spike protein on their cell surface, which will interact with ACE2 on neighboring cells, leading to cell membrane fusion and the formation of multinucleated cells or syncytia. Both viral entry and syncytia formation are mediated by spike-ACE2 interaction and share some common mechanisms of membrane fusion. Here in this review, we will summarize our current understanding of spike-mediated membrane fusion, which may shed light on future broad-spectrum antiviral development.


Subject(s)
COVID-19 , Humans , SARS-CoV-2/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Membrane Fusion , Spike Glycoprotein, Coronavirus/metabolism , Protein Binding , Virus Internalization
13.
Amino Acids ; 55(5): 595-606, 2023 May.
Article in English | MEDLINE | ID: mdl-36809562

ABSTRACT

Ornithine metabolism plays a vital role in tumorigenesis. For cancer cells, ornithine is mainly used as a substrate for ornithine decarboxylase (ODC) for the synthesis of polyamines. The ODC as a key enzyme of polyamine metabolism has become an important target for cancer diagnosis and treatment. To non-invasively detect the levels of ODC expression in malignant tumors, we have synthesized a novel 68Ga-labeled ornithine derivative ([68Ga]Ga-NOTA-Orn). The synthesis time of [68Ga]Ga-NOTA-Orn was about 30 min with a radiochemical yield of 45-50% (uncorrected), and the radiochemical purity was > 98%. [68Ga]Ga-NOTA-Orn was stable in saline and rat serum. Cellular uptake and competitive inhibition assays using DU145 and AR42J cells demonstrated that the transport pathway of [68Ga]Ga-NOTA-Orn was similar to that of L-ornithine, and it could interact with the ODC after transporting into the cell. Biodistribution and micro-positron emission tomography (Micro-PET) imaging studies showed that [68Ga]Ga-NOTA-Orn exhibited rapid tumor uptake and was rapidly excreted through the urinary system. All above results suggested that [68Ga]Ga-NOTA-Orn is a novel amino acid metabolic imaging agent with great potential of tumor diagnosis.


Subject(s)
Gallium Radioisotopes , Neoplasms , Rats , Animals , Gallium Radioisotopes/chemistry , Ornithine , Tissue Distribution , Positron-Emission Tomography/methods , Neoplasms/diagnostic imaging
14.
Cell ; 133(2): 235-49, 2008 Apr 18.
Article in English | MEDLINE | ID: mdl-18423196

ABSTRACT

Multiple lung pathogens such as chemical agents, H5N1 avian flu, or SARS cause high lethality due to acute respiratory distress syndrome. Here we report that Toll-like receptor 4 (TLR4) mutant mice display natural resistance to acid-induced acute lung injury (ALI). We show that TLR4-TRIF-TRAF6 signaling is a key disease pathway that controls the severity of ALI. The oxidized phospholipid (OxPL) OxPAPC was identified to induce lung injury and cytokine production by lung macrophages via TLR4-TRIF. We observed OxPL production in the lungs of humans and animals infected with SARS, Anthrax, or H5N1. Pulmonary challenge with an inactivated H5N1 avian influenza virus rapidly induces ALI and OxPL formation in mice. Loss of TLR4 or TRIF expression protects mice from H5N1-induced ALI. Moreover, deletion of ncf1, which controls ROS production, improves the severity of H5N1-mediated ALI. Our data identify oxidative stress and innate immunity as key lung injury pathways that control the severity of ALI.


Subject(s)
Oxidative Stress , Respiratory Distress Syndrome/metabolism , Toll-Like Receptor 4/metabolism , Adaptor Proteins, Vesicular Transport/metabolism , Animals , Humans , Influenza, Human/metabolism , Interleukin-6/metabolism , Lung , Mice , Mice, Inbred C57BL , NADPH Oxidases/metabolism , NF-kappa B/metabolism , Orthomyxoviridae Infections/metabolism , Phospholipids/metabolism , Severe Acute Respiratory Syndrome/metabolism , Signal Transduction
15.
J Nat Prod ; 86(2): 429-433, 2023 02 24.
Article in English | MEDLINE | ID: mdl-36729068

ABSTRACT

Territrem F (1), a drimane meroterpenoid bearing a unique borate ring system, was isolated together with its diol precursor territrem B (2) from the fungus Alternaria sp. ZH-15 associated with the soft coral Lobophytum crassum collected in the South China Sea. The structure of the new compound was elucidated by spectroscopic analysis and an X-ray single-crystal diffraction study, representing a new type of boron-containing natural product. Both compounds significantly inhibited spontaneous synchronous Ca2+ oscillations (SCOs) and epileptic discharges induced by 4-aminopyridine, showing the potential for antiepileptic drug research. The 5,9-boronic ester derivative of 2 did not change its SCO inhibitory activity.


Subject(s)
Agaricales , Anthozoa , Diterpenes , Animals , Molecular Structure , Diterpenes/chemistry , Borates , Alternaria , Anthozoa/chemistry
16.
Nucleic Acids Res ; 49(19): 11367-11378, 2021 11 08.
Article in English | MEDLINE | ID: mdl-34614154

ABSTRACT

Bacterial chromosome replication is mainly catalyzed by DNA polymerase III, whose beta subunits enable rapid processive DNA replication. Enabled by the clamp-loading complex, the two beta subunits form a ring-like clamp around DNA and keep the polymerase sliding along. Given the essential role of ß-clamp, its inhibitors have been explored for antibacterial purposes. Similarly, ß-clamp is an ideal target for bacteriophages to shut off host DNA synthesis during host takeover. The Gp168 protein of phage Twort is such an example, which binds to the ß-clamp of Staphylococcus aureus and prevents it from loading onto DNA causing replication arrest. Here, we report a cryo-EM structure of the clamp-Gp168 complex at 3.2-Å resolution. In the structure of the complex, the Gp168 dimer occupies the DNA sliding channel of ß-clamp and blocks its loading onto DNA, which represents a new inhibitory mechanism against ß-clamp function. Interestingly, the key residues responsible for this interaction on the ß-clamp are well conserved among bacteria. We therefore demonstrate that Gp168 is potentially a cross-species ß-clamp inhibitor, as it forms complex with the Bacillus subtilis ß-clamp. Our findings reveal an alternative mechanism for bacteriophages to inhibit ß-clamp and provide a new strategy to combat bacterial drug resistance.


Subject(s)
Bacillus subtilis/drug effects , Bacteriophages/chemistry , DNA, Bacterial/chemistry , Escherichia coli/drug effects , Staphylococcus aureus/drug effects , Viral Proteins/chemistry , Amino Acid Sequence , Bacillus subtilis/genetics , Bacillus subtilis/metabolism , Bacteriophages/genetics , Bacteriophages/metabolism , Binding Sites , Cloning, Molecular , Cryoelectron Microscopy , DNA Polymerase III/antagonists & inhibitors , DNA Polymerase III/genetics , DNA Polymerase III/metabolism , DNA Replication/drug effects , DNA, Bacterial/genetics , DNA, Bacterial/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism , Gene Expression , Genetic Vectors/chemistry , Genetic Vectors/metabolism , Models, Molecular , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , Protein Multimerization , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequence Alignment , Sequence Homology, Amino Acid , Staphylococcus aureus/genetics , Staphylococcus aureus/metabolism , Viral Proteins/genetics , Viral Proteins/metabolism , Viral Proteins/pharmacology
17.
BMC Musculoskelet Disord ; 24(1): 723, 2023 Sep 11.
Article in English | MEDLINE | ID: mdl-37697276

ABSTRACT

BACKGROUND: Cervical stiffness, coronal imbalance and limited hip movement all play crucial roles in designing the corrective surgery for ankylosing spondylitis-related thoracolumbar kyphosis (AS-TLK). However, a comprehensive classification and tailored strategies for directing clinical work are lacking. This study aims to investigate the types and surgical strategies for AS-TLK that consider cervical stiffness, coronal imbalance and hip involvement as the key factors. METHODS: 25 consecutive AS-TLK patients were divided into three types according to their accompanying features: Type I: with a flexible cervical spine; Type IIA: with a stiff cervical spine; Type IIB: with coronal imbalance; Type IIC: with limited hip movement. Type III is the mixed type with at least two conditions of Type II. Individual strategies were given correspondingly. Spinal-pelvic-femoral parameters were measured, Scoliosis Research Society outcome instrument-22 (SRS-22) was used and complications were recorded and analysed. RESULTS: All patients (Type I 10, Type II 8 and Type III 7) underwent surgery successfully. 13 cases with 16 complications were recorded and cured. The patients were followed up for 24-65 months with an average of 33.0 ± 9.6 months. Both the sagittal and coronal parameters were corrected and decreased significantly (all, p < 0.05). SRS-22 scores showed a satisfactory outcome. CONCLUSION: Thoracolumbar kyphosis secondary to ankylosing spondylitis are complex and variable. Considering the factors of cervical stiffness, coronal imbalance and hip involvement assists in making decisions individually and achieving a desired surgical result.


Subject(s)
Kyphosis , Spondylitis, Ankylosing , Humans , Spondylitis, Ankylosing/complications , Spondylitis, Ankylosing/diagnostic imaging , Spondylitis, Ankylosing/surgery , Neck , Kyphosis/diagnostic imaging , Kyphosis/etiology , Kyphosis/surgery , Cervical Vertebrae/diagnostic imaging , Cervical Vertebrae/surgery , Decision Making
18.
Ecotoxicol Environ Saf ; 249: 114395, 2023 Jan 01.
Article in English | MEDLINE | ID: mdl-36508783

ABSTRACT

Traditional Chinese medicine (TCM) is still considered a global complementary or alternative medical system, but exogenous hazardous contaminants remain in TCM even after decocting. Besides, it is time-consuming to conduct a risk assessment of trace elements in TCMs with a non-automatic approach due to the wide variety of TCMs. Here, we present MRTCM, a cloud-computing infrastructure for automating the probabilistic risk assessment of metals and metalloids in TCM. MRTCM includes a consumption database and a pollutant database involving forty million rows of consumption data and fourteen types of TCM potentially toxic elements concentrations. The algorithm of probabilistic risk assessment was also packaged in MRTCM to assess the risks of eight elements with Monte Carlo simulation. The results demonstrated that 96.64% and 99.46% had no non-carcinogenic risk (hazard indices (HI) were < 1.0) for animal and herbal medicines consumers, respectively. After twenty years of exposure, less than 1% of the total carcinogenic risk (CRt) was > 10-4 for TCM consumers, indicating that they are at potential risk for carcinogenicity. Sensitivity analysis revealed that annual consumption and concentration were the main variables affecting the assessment results. Ultimately, a priority management list of TCMs was also generated, indicating that more attention should be paid to the non-carcinogenic risks of As, Mn, and Hg and the carcinogenic risks of As and Cr in Pheretima and Cr in Arcae Conch. In general, MRTCM could significantly enhance the efficiency of risk assessment in TCM and provide reasonable guidance for policymakers to optimize risk management.


Subject(s)
Mercury , Metalloids , Metals, Heavy , Animals , Metals, Heavy/toxicity , Metals, Heavy/analysis , Medicine, Chinese Traditional , Metalloids/analysis , Mercury/analysis , Risk Assessment , Carcinogens/analysis , Environmental Monitoring/methods
19.
J Insect Sci ; 23(3)2023 May 01.
Article in English | MEDLINE | ID: mdl-37335595

ABSTRACT

The juvenile hormone (JH) plays a vital role in the regulation of a number of physiological processes, including development, reproduction, and ovarian maturation. Isopentenyl pyrophosphate isomerase (IPPI) is a key enzyme in the biosynthetic pathway of JH. In this study, we identified an isopentenyl pyrophosphate isomerase protein from Bemisia tabaci and named it BtabIPPI. The open reading frame (ORF) of BtabIPPI is 768 bp and encodes a protein of 255 amino acids that contains a conserved domain of the Nudix family. The temporal and spatial expression profiles showed that BtabIPPI was highly expressed in the female adults.RNA interference (RNAi)-mediated silencing of BtabIPPI reduced JH titers and the relative expression of vitellogenin receptor (VgR) and JH signaling pathway genes, resulting in a dramatic reduction in fecundity and hatchability. These results indicate that the BtabIPPI gene plays an important role in the female fecundity of B. tabaci. This study will broaden our understanding of the function of IPPI in regulating insect reproduction and provide a theoretical basis for targeting IPPI for pest control in the future.


Subject(s)
Carbon-Carbon Double Bond Isomerases , Hemiptera , Female , Animals , Hemiptera/physiology , RNA Interference , Carbon-Carbon Double Bond Isomerases/genetics , Carbon-Carbon Double Bond Isomerases/metabolism , Hemiterpenes/metabolism
20.
Sensors (Basel) ; 23(24)2023 Dec 18.
Article in English | MEDLINE | ID: mdl-38139740

ABSTRACT

Surface acoustic wave resonators are widely applied in electronics, communication, and other engineering fields. However, the spurious modes generally present in resonators can cause deterioration in device performance. Therefore, this paper proposes a hexagonal weighted structure to suppress them. With the construction of a finite element resonator model, the parameters of the interdigital transducer (IDT) and the area of the dummy finger weighting are determined. The spurious waves are confined within the dummy finger area, whereas the main mode is less affected by this structure. To verify the suppression effect of the simulation, resonators with conventional and hexagonal weighted structures are fabricated using the micro-electromechanical systems (MEMS) process. After the S-parameter test of the prepared resonators, the hexagonal weighted resonators achieve a high level of spurious mode suppression. Their properties are superior to those of the conventional structure, with a higher Q value (10,406), a higher minimum return loss (25.7 dB), and a lower ratio of peak sidelobe (19%). This work provides a feasible solution for the design of SAW resonators to suppress spurious modes.

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