Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.028
Filter
Add more filters

Publication year range
1.
Nat Immunol ; 18(12): 1299-1309, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28967880

ABSTRACT

NLRX1 is unique among the nucleotide-binding-domain and leucine-rich-repeat (NLR) proteins in its mitochondrial localization and ability to negatively regulate antiviral innate immunity dependent on the adaptors MAVS and STING. However, some studies have suggested a positive regulatory role for NLRX1 in inducing antiviral responses. We found that NLRX1 exerted opposing regulatory effects on viral activation of the transcription factors IRF1 and IRF3, which might potentially explain such contradictory results. Whereas NLRX1 suppressed MAVS-mediated activation of IRF3, it conversely facilitated virus-induced increases in IRF1 expression and thereby enhanced control of viral infection. NLRX1 had a minimal effect on the transcription of IRF1 mediated by the transcription factor NF-kB and regulated the abundance of IRF1 post-transcriptionally by preventing translational shutdown mediated by the double-stranded RNA (dsRNA)-activated kinase PKR and thereby allowed virus-induced increases in the abundance of IRF1 protein.


Subject(s)
Hepacivirus/immunology , Hepatitis C/immunology , Immunity, Innate/immunology , Interferon Regulatory Factor-1/immunology , Interferon Regulatory Factor-3/immunology , Mitochondrial Proteins/immunology , Adaptor Proteins, Signal Transducing/immunology , Animals , Cells, Cultured , Enzyme Activation/immunology , HEK293 Cells , Hepatitis C/virology , Hepatocytes/immunology , Hepatocytes/virology , Humans , Interferon Regulatory Factor-1/metabolism , Mice , Mice, Knockout , Mitochondrial Proteins/genetics , NF-kappa B/metabolism , RNA, Viral/genetics , Sendai virus/immunology , eIF-2 Kinase/metabolism
2.
Proc Natl Acad Sci U S A ; 121(13): e2316912121, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38502698

ABSTRACT

Multi-principal element alloys (MPEAs) exhibit outstanding strength attributed to the complex dislocation dynamics as compared to conventional alloys. Here, we develop an atomic-lattice-distortion-dependent discrete dislocation dynamics framework consisted of random field theory and phenomenological dislocation model to investigate the fundamental deformation mechanism underlying massive dislocation motions in body-centered cubic MPEA. Amazingly, the turbulence of dislocation speed is identified in light of strong heterogeneous lattice strain field caused by short-range ordering. Importantly, the vortex from dislocation flow turbulence not only acts as an effective source to initiate dislocation multiplication but also induces the strong local pinning trap to block dislocation movement, thus breaking the strength-ductility trade-off.

3.
Nature ; 584(7819): 120-124, 2020 08.
Article in English | MEDLINE | ID: mdl-32454512

ABSTRACT

An outbreak of coronavirus disease 2019 (COVID-19)1-3, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)4, has spread globally. Countermeasures are needed to treat and prevent further dissemination of the virus. Here we report the isolation of two specific human monoclonal antibodies (termed CA1 and CB6) from a patient convalescing from COVID-19. CA1 and CB6 demonstrated potent SARS-CoV-2-specific neutralization activity in vitro. In addition, CB6 inhibited infection with SARS-CoV-2 in rhesus monkeys in both prophylactic and treatment settings. We also performed structural studies, which revealed that CB6 recognizes an epitope that overlaps with angiotensin-converting enzyme 2 (ACE2)-binding sites in the SARS-CoV-2 receptor-binding domain, and thereby interferes with virus-receptor interactions by both steric hindrance and direct competition for interface residues. Our results suggest that CB6 deserves further study as a candidate for translation to the clinic.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/immunology , Coronavirus Infections/virology , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/pharmacology , Antibodies, Viral/chemistry , Antibodies, Viral/pharmacology , Betacoronavirus/chemistry , Binding, Competitive , COVID-19 , Cell Line , Chlorocebus aethiops , Crystallization , Crystallography, X-Ray , Female , Humans , In Vitro Techniques , Macaca mulatta/immunology , Macaca mulatta/virology , Male , Models, Molecular , Neutralization Tests , Pandemics , Peptidyl-Dipeptidase A/chemistry , Peptidyl-Dipeptidase A/metabolism , Protein Binding/drug effects , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Spike Glycoprotein, Coronavirus/metabolism , Vero Cells , Viral Load/immunology
4.
Nano Lett ; 24(14): 4082-4090, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38526914

ABSTRACT

The generally nonpolar SrTiO3 has attracted more attention recently because of its possibly induced novel polar states and related paraelectric-ferroelectric phase transitions. By using controlled pulsed laser deposition, high-quality, ultrathin, and strained SrTiO3 layers were obtained. Here, transmission electron microscopy and theoretical simulations have unveiled highly polar states in SrTiO3 films even down to one unit cell at room temperature, which were stabilized in the PbTiO3/SrTiO3/PbTiO3 sandwich structures by in-plane tensile strain and interfacial coupling, as evidenced by large tetragonality (∼1.05), notable polar ion displacement (0.019 nm), and thus ultrahigh spontaneous polarization (up to ∼50 µC/cm2). These values are nearly comparable to those of the strong ferroelectrics as the PbZrxTi1-xO3 family. Our findings provide an effective and practical approach for integrating large strain states into oxide films and inducing polarization in nonpolar materials, which may broaden the functionality of nonpolar oxides and pave the way for the discovery of new electronic materials.

5.
BMC Plant Biol ; 24(1): 366, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38711037

ABSTRACT

BACKGROUND: Nitrogen (N) is essential for plant growth and development. In Lithocarpus polystachyus Rehd., a species known for its medicinal and food value, phlorizin is the major bioactive compound with pharmacological activity. Research has revealed a positive correlation between plant nitrogen (N) content and phlorizin synthesis in this species. However, no study has analyzed the effect of N fertilization on phlorizin content and elucidated the molecular mechanisms underlying phlorizin synthesis in L. polystachyus. RESULTS: A comparison of the L. polystachyus plants grown without (0 mg/plant) and with N fertilization (25, 75, 125, 175, 225, and 275 mg/plant) revealed that 75 mg N/plant fertilization resulted in the greatest seedling height, ground diameter, crown width, and total phlorizin content. Subsequent analysis of the leaves using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) detected 150 metabolites, including 42 flavonoids, that were differentially accumulated between the plants grown without and with 75 mg/plant N fertilization. Transcriptomic analysis of the L. polystachyus plants via RNA sequencing revealed 162 genes involved in flavonoid biosynthesis, among which 53 significantly differed between the N-treated and untreated plants. Fertilization (75 mg N/plant) specifically upregulated the expression of the genes phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL), and phlorizin synthase (PGT1) but downregulated the expression of trans-cinnamate 4-monooxygenase (C4H), shikimate O-hydroxycinnamoyltransferase (HCT), and chalcone isomerase (CHI), which are related to phlorizin synthesis. Finally, an integrated analysis of the transcriptome and metabolome revealed that the increase in phlorizin after N fertilization was consistent with the upregulation of phlorizin biosynthetic genes. Quantitative real-time PCR (qRT‒PCR) was used to validate the RNA sequencing data. Thus, our results indicated that N fertilization increased phlorizin metabolism in L. polystachyus by regulating the expression levels of the PAL, PGT1, 5-O-(4-coumaroyl)-D-quinate 3'-monooxygenase (C3'H), C4H, and HCT genes. CONCLUSIONS: Our results demonstrated that the addition of 75 mg/plant N to L. polystachyus significantly promoted the accumulation of flavonoids, including phlorizin, and the expression of flavonoid synthesis-related genes. Under these conditions, the genes PAL, 4CL, and PGT1 were positively correlated with phlorizin accumulation, while C4H, CHI, and HCT were negatively correlated with phlorizin accumulation. Therefore, we speculate that PAL, 4CL, and PGT1 participate in the phlorizin pathway under an optimal N environment, regulating phlorizin biosynthesis. These findings provide a basis for improving plant bioactive constituents and serve as a reference for further pharmacological studies.


Subject(s)
Fertilizers , Metabolome , Nitrogen , Phlorhizin , Transcriptome , Nitrogen/metabolism , Metabolome/drug effects , Gene Expression Regulation, Plant/drug effects , Gene Expression Profiling , Tandem Mass Spectrometry , Plant Proteins/genetics , Plant Proteins/metabolism
6.
Plant Biotechnol J ; 22(7): 1913-1925, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38366362

ABSTRACT

Potato is the third most important food crop worldwide. Potato production suffers from severe diseases caused by multiple detrimental plant pathogens, and broad-spectrum disease resistance genes are rarely identified in potato. Here we identified the potato non-specific lipid transfer protein StLTPa, which enhances species none-specific disease resistance against various pathogens, such as the oomycete pathogen Phytophthora infestans, the fungal pathogens Botrytis cinerea and Verticillium dahliae, and the bacterial pathogens Pectobacterium carotovorum and Ralstonia solanacearum. The StLTPa overexpression potato lines do not show growth penalty. Furthermore, we provide evidence that StLTPa binds to lipids present in the plasma membrane (PM) of the hyphal cells of P. infestans, leading to an increased permeability of the PM. Adding of PI(3,5)P2 and PI(3)P could compete the binding of StLTPa to pathogen PM and reduce the inhibition effect of StLTPa. The lipid-binding activity of StLTPa is essential for its role in pathogen inhibition and promotion of potato disease resistance. We propose that StLTPa enhances potato broad-spectrum disease resistance by binding to, and thereby promoting the permeability of the PM of the cells of various pathogens. Overall, our discovery illustrates that increasing the expression of a single gene in potato enhances potato disease resistance against different pathogens without growth penalty.


Subject(s)
Carrier Proteins , Cell Membrane , Disease Resistance , Phytophthora infestans , Plant Diseases , Plant Proteins , Solanum tuberosum , Solanum tuberosum/microbiology , Solanum tuberosum/genetics , Solanum tuberosum/metabolism , Solanum tuberosum/immunology , Disease Resistance/genetics , Plant Diseases/microbiology , Plant Diseases/immunology , Cell Membrane/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Phytophthora infestans/pathogenicity , Carrier Proteins/metabolism , Carrier Proteins/genetics , Ralstonia solanacearum/pathogenicity , Ralstonia solanacearum/physiology , Botrytis , Plants, Genetically Modified , Pectobacterium carotovorum
7.
PLoS Pathog ; 18(8): e1010543, 2022 08.
Article in English | MEDLINE | ID: mdl-35969644

ABSTRACT

Although picornaviruses are conventionally considered 'nonenveloped', members of multiple picornaviral genera are released nonlytically from infected cells in extracellular vesicles. The mechanisms underlying this process are poorly understood. Here, we describe interactions of the hepatitis A virus (HAV) capsid with components of host endosomal sorting complexes required for transport (ESCRT) that play an essential role in release. We show release of quasi-enveloped virus (eHAV) in exosome-like vesicles requires a conserved export signal located within the 8 kDa C-terminal VP1 pX extension that functions in a manner analogous to late domains of canonical enveloped viruses. Fusing pX to a self-assembling engineered protein nanocage (EPN-pX) resulted in its ESCRT-dependent release in extracellular vesicles. Mutational analysis identified a 24 amino acid peptide sequence located within the center of pX that was both necessary and sufficient for nanocage release. Deleting a YxxL motif within this sequence ablated eHAV release, resulting in virus accumulating intracellularly. The pX export signal is conserved in non-human hepatoviruses from a wide range of mammalian species, and functional in pX sequences from bat hepatoviruses when fused to the nanocage protein, suggesting these viruses are released as quasi-enveloped virions. Quantitative proteomics identified multiple ESCRT-related proteins associating with EPN-pX, including ALG2-interacting protein X (ALIX), and its paralog, tyrosine-protein phosphatase non-receptor type 23 (HD-PTP), a second Bro1 domain protein linked to sorting of ubiquitylated cargo into multivesicular endosomes. RNAi-mediated depletion of either Bro1 domain protein impeded eHAV release. Super-resolution fluorescence microscopy demonstrated colocalization of viral capsids with endogenous ALIX and HD-PTP. Co-immunoprecipitation assays using biotin-tagged peptides and recombinant proteins revealed pX interacts directly through the export signal with N-terminal Bro1 domains of both HD-PTP and ALIX. Our study identifies an exceptionally potent viral export signal mediating extracellular release of virus-sized protein assemblies and shows release requires non-redundant activities of both HD-PTP and ALIX.


Subject(s)
Endosomal Sorting Complexes Required for Transport , Hepatitis A virus , Animals , Calcium-Binding Proteins/metabolism , Capsid/metabolism , Capsid Proteins/genetics , Capsid Proteins/metabolism , Cell Cycle Proteins/metabolism , Endosomal Sorting Complexes Required for Transport/genetics , Endosomal Sorting Complexes Required for Transport/metabolism , Hepatitis A virus/genetics , Hepatitis A virus/metabolism , Mammals , Viral Proteins/metabolism
8.
J Med Virol ; 96(6): e29712, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38808555

ABSTRACT

Swine acute diarrhea syndrome coronavirus (SADS-CoV) has caused severe intestinal diseases in pigs. It originates from bat coronaviruses HKU2 and has a potential risk of cross-species transmission, raising concerns about its zoonotic potential. Viral entry-related host factors are critical determinants of susceptibility to cells, tissues, or species, and remain to be elucidated for SADS-CoV. Type II transmembrane serine proteases (TTSPs) family is involved in many coronavirus infections and has trypsin-like catalytic activity. Here we examine all 18 members of the TTSPs family through CRISPR-based activation of endogenous protein expression in cells, and find that, in addition to TMPRSS2 and TMPRSS4, TMPRSS13 significantly facilitates SADS-CoV infection. This is confirmed by ectopic expression of TMPRSS13, and specific to trypsin-dependent SADS-CoV. Infection with pseudovirus bearing SADS-CoV spike protein indicates that TMPRSS13 acts at the entry step and is sensitive to serine protease inhibitor Camostat. Moreover, both human and pig TMPRSS13 are able to enhance the cell-cell membrane fusion and cleavage of spike protein. Overall, we demonstrate that TMPRSS13 is another host serine protease promoting the membrane-fusion entry of SADS-CoV, which may expand its host tropism by using diverse TTSPs.


Subject(s)
Membrane Proteins , Serine Endopeptidases , Virus Internalization , Animals , Serine Endopeptidases/metabolism , Serine Endopeptidases/genetics , Swine , Humans , Membrane Proteins/metabolism , Membrane Proteins/genetics , Alphacoronavirus/genetics , Alphacoronavirus/physiology , Coronavirus Infections/virology , Coronavirus Infections/metabolism , Gabexate/analogs & derivatives , Gabexate/pharmacology , Spike Glycoprotein, Coronavirus/metabolism , Spike Glycoprotein, Coronavirus/genetics , HEK293 Cells , Cell Line , Chlorocebus aethiops , Swine Diseases/virology , Esters , Guanidines
9.
Opt Express ; 32(3): 3606-3618, 2024 Jan 29.
Article in English | MEDLINE | ID: mdl-38297578

ABSTRACT

In this paper, we present the bit error rate (BER) performance of the underwater wireless optical communication (UWOC) systems using the optical space shift keying (OSSK) on the gamma-gamma turbulent fading channel, which also considers pointing errors and channel estimation errors. Firstly, we develop the new expressions for the probability density function (PDF) based on the Gamma-Gamma distribution with error factors. Subsequently, we analyze the statistical characteristic of the difference in attenuation coefficients between two channels in the OSSK system, by which we provide analytical results for evaluating the average BER performance. The results show that the effective improvement of spectral efficiency (SE) and BER performance is achieved by rationally allocating the number of lasers and detectors in the system. The OSSK-UWOC system performs better when a narrow beam waist is used. Furthermore, the presence of channel estimation error brings the BER performance advantage to the system, and the system with a high channel estimation error (ρ = 0.7) shows a 4 dB improvement in signal-to-noise ratio (SNR) gain compared to the system with a low channel estimation error (ρ = 0.95). The findings in this paper can be used for the UWOC system design.

10.
Opt Express ; 32(3): 3874-3890, 2024 Jan 29.
Article in English | MEDLINE | ID: mdl-38297599

ABSTRACT

This paper investigates the propagation of Gaussian array beams (GABs) through seawater-to-air in the presence of oceanic turbulence, atmospheric turbulence, and wave foams. Specifically, we focus on the intensity distribution of diverse typical GAB structures (ring, multi-ring, and rectangle). Then, an innovative intensity analysis model to calculate the average intensity in each medium is proposed. Moreover, we experimentally verify the proposed method by examining the intensity fading characteristic of Gaussian beams in the seawater-to-air path. Our results show that the peak intensity is primarily affected by the refraction in the ocean and foam layer, rather than air layer. The difference of theoretical and experimental values are less than 0.13 for the peak intensity. Moreover, the intensity distributions are more significantly affected by ocean turbulence but less influenced by wind speed.

11.
Opt Express ; 32(4): 5230-5241, 2024 Feb 12.
Article in English | MEDLINE | ID: mdl-38439255

ABSTRACT

A vector optical field with inhomogeneous spatial polarization distribution offers what we believe to be a new paradigm to form controllable filaments. However, it is challenging to steer multiple performances (e.g. number, orientation, and interval) of filaments in transparent nonlinear media at one time. Herein, we theoretically self-design and generate a kind of believed to be novel ellipticity and orientation co-variant vector optical field to interact with Kerr medium to solve this issue. The collapsing behaviors of such a new hybrid vector optical field reveal that, by judiciously adjusting the inherent topological charge and initial phase of incident optical field, we are able to give access to stable collapsing filamentation with tunable numbers, orientations and interval. Additionally, the collapsing patterns presented are immune nearly to the extra random noise. The relevant mechanism behind the collapse of the vector optical field is elucidated as well. The findings in this work may have huge potential in optical signal processing, laser machining, and other related applications.

12.
Theor Appl Genet ; 137(2): 44, 2024 Feb 07.
Article in English | MEDLINE | ID: mdl-38324148

ABSTRACT

KEY MESSAGE: BrFLS mutation promoted anthocyanin accumulation in Chinese cabbage, which was verified in four allelic mutants. Chinese cabbage is a major vegetable crop in Eastern Asia. Anthocyanin-rich vibrantly colored varieties are increasingly favored by consumers for their higher nutritional and aesthetic value compared to the typical green varieties of Chinese cabbage. Herein, we identified an anthocyanin accumulation mutant aam1 from a mutant library of EMS-mutagenized Chinese cabbage DH line 'FT', which appeared partial purple on leaves, bolting stems and floral buds. This anthocyanin accumulation trait was genetically controlled by a recessive nuclear gene, and through MutMap mapping and KASP genotyping, BraA10g030950.3C was identified as the candidate causal gene with a G202 to A202 non-synonymous SNP variation in exon 1. Three additional mutants allelic to aam1 were obtained via screening of similar-phenotype mutants from the mutant library, namely aam2/3/4, where the causal SNPs reside in the same gene as aam1, corroborating that the mutation of BraA10g030950.3C caused anthocyanin accumulation. BraA10g030950.3C encodes a flavonol synthase that catalyzes dihydroflavonols substrate into flavonols and is homologous to Arabidopsis FLS1 (AT5G08640), named BrFLS. Compared to wildtype, the expression level of BrFLS was significantly reduced in the mutants, while BrDFR, which is involved in the anthocyanin biosynthesis and competes with FLS for the common substrate dihydroflavonols, was increased. The flavonol synthase activity decreased, and dihydroflavonol 4-reductase activity was elevated. Differentially accumulated flavonoid metabolites were detected between wildtype and aam1, which were enriched primarily in flavonol and anthocyanin pathways. Our results revealed that mutations in the BrFLS gene could contribute to anthocyanin accumulation and provide a new target for Chinese cabbage color modification.


Subject(s)
Brassica , Oxidoreductases , Plant Proteins , Anthocyanins , Brassica/enzymology , Brassica/genetics , Flavonoids , Mutation , Oxidoreductases/genetics , Plant Proteins/genetics
13.
Theor Appl Genet ; 137(6): 123, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38722407

ABSTRACT

KEY MESSAGE: BrBCAT1 encoding a branched-chain amino acid aminotransferase was responsible for the glossy trait, which was verified by allelic mutants in Chinese cabbage. The glossy characteristic, thanks to the epicuticular wax crystal deficiency, is an excellent commodity character for leafy vegetables. Herein, two allelic glossy green mutants, wdm11 and wdm12, were isolated from an ethyl methane sulfonate (EMS)-mutagenized population of Chinese cabbage, and the mutant phenotype was recessive inherited. Cryo-SEM detected that epicuticular wax crystal in the mutant leaves was virtually absent. MutMap and Kompetitive allele-specific PCR analyses demonstrated that BraA06g006950.3C (BrBCAT1), homologous to AtBCAT1, encoding a branched-chain amino acid aminotransferase was the candidate gene. A SNP (G to A) on the fourth exon of BrBCAT1 in wdm11 caused the 233rd amino acid to change from glycine (G) to aspartic acid (D). A SNP (G to A) on the second exon of BrBCAT1 in wdm12 led to the 112th amino acid change from glycine (G) to arginine (R). Both of the allelic mutants had genetic structural variation in the candidate gene, which indicated that the mutant phenotype was triggered by the BrBCAT1 mutation. The expression levels of BrBCAT1 and genes related to fatty acid chain extension were decreased significantly in the mutant compared to the wild-type, which might result in epicuticular wax crystal deficiency in the mutants. Our findings proved that the mutation of BrBCAT1 induced the glossy phenotype and provided a valuable gene resource for commodity character improvement in Chinese cabbage.


Subject(s)
Brassica , Plant Leaves , Transaminases , Waxes , Alleles , Brassica/genetics , Mutation , Phenotype , Plant Leaves/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Plant Proteins/chemistry , Polymorphism, Single Nucleotide , Transaminases/genetics , Waxes/chemistry , Waxes/metabolism
14.
Theor Appl Genet ; 137(3): 63, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38427048

ABSTRACT

KEY MESSAGE: The gene BrABCG26 responsible for male sterility of Chinese cabbage was confirmed by two allelic mutants. Male-sterile lines are an important way of heterosis utilization in Chinese cabbage. In this study, two allelic male-sterile mutants msm3-1 and msm3-2 were obtained from a Chinese cabbage double haploid (DH) line 'FT' by using EMS-mutagenesis. Compared to the wild-type 'FT,' the stamens of mutants were completely degenerated and had no pollen, and other characters had no obvious differences. Cytological observation revealed that the failure of vacuolation of the mononuclear microspore, accompanied by abnormal tapetal degradation, resulted in anther abortion in mutants. Genetic analysis showed that a recessive gene controlled the mutant trait. MutMap combined with kompetitive allele specific PCR genotyping analyses showed that BraA01g038270.3C, encoding a transporter ABCG26 that played a vital role in pollen wall formation, was the candidate gene for msm3-1, named BrABCG26. Compared with wild-type 'FT,' the mutations existed on the second exon (C to T) and the sixth exon (C to T) of BrABCG26 gene in mutants msm3-1 and msm3-2, leading to the loss-of-function truncated protein, which verified the BrABCG26 function in stamen development. Subcellular localization and expression pattern analysis indicated that BrABCG26 was localized in the nucleus and was expressed in all organs, with the highest expression in flower buds. Compared to the wild-type 'FT,' the expressions of BrABCG26 were significantly reduced in flower buds and anthers of mutants. Promoter activity analysis showed that a strong GUS signal was detected in flower buds. These results indicated that BrABCG26 is responsible for the male sterility of msm3 mutants in Chinese cabbage.


Subject(s)
Brassica rapa , Brassica , Infertility, Male , Male , Humans , Brassica rapa/genetics , Gene Expression Profiling/methods , ATP-Binding Cassette Transporters/genetics , Plant Proteins/genetics , Brassica/genetics , Mutation , Gene Expression Regulation, Plant , Plant Infertility/genetics
15.
EMBO Rep ; 23(2): e53499, 2022 02 03.
Article in English | MEDLINE | ID: mdl-34882936

ABSTRACT

The activation of the nucleotide oligomerization domain (NOD)-like receptor (NLR) family, pyrin domain-containing protein 3 (NLRP3) inflammasome is related to the pathogenesis of a wide range of inflammatory diseases, but drugs targeting the NLRP3 inflammasome are still scarce. In the present study, we demonstrated that Licochalcone B (LicoB), a main component of the traditional medicinal herb licorice, is a specific inhibitor of the NLRP3 inflammasome. LicoB inhibits the activation of the NLRP3 inflammasome in macrophages but has no effect on the activation of AIM2 or NLRC4 inflammasome. Mechanistically, LicoB directly binds to NEK7 and inhibits the interaction between NLRP3 and NEK7, thus suppressing NLRP3 inflammasome activation. Furthermore, LicoB exhibits protective effects in mouse models of NLRP3 inflammasome-mediated diseases, including lipopolysaccharide (LPS)-induced septic shock, MSU-induced peritonitis and non-alcoholic steatohepatitis (NASH). Our findings indicate that LicoB is a specific NLRP3 inhibitor and a promising candidate for treating NLRP3 inflammasome-related diseases.


Subject(s)
Chalcones , Inflammasomes , Animals , Chalcones/pharmacology , Inflammasomes/metabolism , Mice , Mice, Inbred C57BL , NIMA-Related Kinases/genetics , NIMA-Related Kinases/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein
16.
Ann Bot ; 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38507570

ABSTRACT

BACKGROUNDS AND AIMS: The hypothesis that plants evolve features that protect accessible pollen from consumption by flower visitors remains poorly understood. METHODS: To explore potential chemical defenses against pollen consumption, we examined the pollinator assemblage, foraging behaviour, visitation frequency and pollen transfer efficiency in Rhododendron molle, a highly toxic shrub containing Rhodojaponin III. Nutrient (protein and lipid) and toxic components in pollen and other tissues were measured. KEY RESULTS: Overall in the five populations, floral visits by butterflies and bumblebees were relatively more frequent than visits by honeybees. All foraged for nectar but not pollen. Butterflies did not differ from bumblebees in the amount of pollen removed per visit, but deposited more pollen per visit. Pollination experiments indicated that R. molle was self-compatible, but both fruit and seed production were pollen limited. Our analysis indicated that the pollen was not protein-poor and had a higher concentration of the toxic compound Rhodojaponin III than petals and leaves, which compound was undetectable in nectar. CONCLUSION: Pollen toxicity in Rhododendron flowers may discourage pollen robbers (bees) from taking the freely accessible pollen grains, while the toxin-free nectar rewards effective pollinators, promoting pollen transfer. This preliminary study supports the hypothesis that chemical defense in pollen would be likely to evolve in species without physical protection from pollinivores.

17.
Nutr Metab Cardiovasc Dis ; 34(4): 850-859, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38161119

ABSTRACT

BACKGROUND AND AIM: Insulin resistance (IR) plays an important role in the atherosclerotic process, and the triglyceride glucose (TyG) index is a reliable indicator of IR and is strongly associated with cardiovascular disease. However, there are few studies regarding the relationship between the TyG index and chronic total coronary occlusion (CTO). Herein, the correlation between the TyG index and CTO, as well as their interactions with other traditional cardiovascular risk factors, were investigated. METHODS AND RESULTS: We enrolled 2691 patients who underwent coronary angiography at Guangyuan Central Hospital from January 2019 to October 2021. TyG index results were used to create three groups using the trichotomous method. CTO was defined as complete occlusion of the coronary artery for ≥3 months. Univariate and multivariate logistic regression models, restricted cubic splines, receiver operating characteristic (ROC) curves, and subgroup analyses was performed. A significant correlation between the TyG index and CTO was noted. The risk of CTO was increased 2.09-fold in the group with the highest TyG compared with the lowest (OR, 2.09; 95 % CI, 1.05-4.17; P = 0.036). In addition, there was a linear dose-response relationship between the TyG index and CTO (nonlinear P = 0.614). The area under the ROC curve was 0.643 (95 % CI, 0.572-0.654). Using subgroup analyses, we observed that the TyG index was associated with a significantly higher risk of CTO in males and smokers. CONCLUSIONS: An elevated TyG index was related to the risk of CTO and may constitute a meaningful predictor of CTO, particularly in males and in smokers.


Subject(s)
Coronary Occlusion , Insulin Resistance , Male , Humans , Coronary Occlusion/diagnostic imaging , Coronary Occlusion/epidemiology , Cross-Sectional Studies , China/epidemiology , Glucose , Triglycerides , Blood Glucose , Risk Factors , Biomarkers
18.
J Nanobiotechnology ; 22(1): 299, 2024 May 30.
Article in English | MEDLINE | ID: mdl-38812031

ABSTRACT

BACKGROUND: Discrepancies in the utilization of reactive oxygen species (ROS) between cancer cells and their normal counterparts constitute a pivotal juncture for the precise treatment of cancer, delineating a noteworthy trajectory in the field of targeted therapies. This phenomenon is particularly conspicuous in the domain of nano-drug precision treatment. Despite substantial strides in employing nanoparticles to disrupt ROS for cancer therapy, current strategies continue to grapple with challenges pertaining to efficacy and specificity. One of the primary hurdles lies in the elevated levels of intracellular glutathione (GSH). Presently, predominant methods to mitigate intracellular GSH involve inhibiting its synthesis or promoting GSH efflux. However, a conspicuous gap remains in the absence of a strategy capable of directly and efficiently clearing GSH. METHODS: We initially elucidated the chemical mechanism underpinning oridonin, a diminutive pharmacological agent demonstrated to perturb reactive oxygen species, through its covalent interaction with glutathione. Subsequently, we employed the incorporation of maleimide-liposomes, renowned for their capacity to disrupt the ROS delivery system, to ameliorate the drug's water solubility and pharmacokinetics, thereby enhancing its ROS-disruptive efficacy. In a pursuit to further refine the targeting for acute myeloid leukemia (AML), we harnessed the maleic imide and thiol reaction mechanism, facilitating the coupling of Toll-like receptor 2 (TLR2) peptides to the liposomes' surface via maleic imide. This strategic approach offers a novel method for the precise removal of GSH, and its enhancement endeavors are directed towards fortifying the precision and efficacy of the drug's impact on AML targets. RESULTS: We demonstrated that this peptide-liposome-small molecule machinery targets AML and consequently induces cell apoptosis both in vitro and in vivo through three disparate mechanisms: (I) Oridonin, as a Michael acceptor molecule, inhibits GSH function through covalent bonding, triggering an initial imbalance of oxidative stress. (II) Maleimide further induces GSH exhaustion, aggravating redox imbalance as a complementary augment with oridonin. (III) Peptide targets TLR2, enhances the directivity and enrichment of oridonin within AML cells. CONCLUSION: The rationally designed nanocomplex provides a ROS drug enhancement and targeted delivery platform, representing a potential solution by disrupting redox balance for AML therapy.


Subject(s)
Diterpenes, Kaurane , Glutathione , Leukemia, Myeloid, Acute , Liposomes , Reactive Oxygen Species , Diterpenes, Kaurane/chemistry , Diterpenes, Kaurane/pharmacology , Glutathione/metabolism , Glutathione/chemistry , Liposomes/chemistry , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/metabolism , Humans , Reactive Oxygen Species/metabolism , Animals , Mice , Cell Line, Tumor , Toll-Like Receptor 2/metabolism , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Apoptosis/drug effects
19.
Cell Mol Biol Lett ; 29(1): 46, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38561669

ABSTRACT

BACKGROUND: Small extracellular vesicles (sEV) are closely associated with the development and metastasis of many types of mammalian cancer. Glycoconjugates are highly expressed on sEV and play important roles in sEV biogenesis and their interaction with other cells. However, the study on vesicular glycoconjugates are far behind proteins and nucleic acids. Especially, the functions of sialic acids which are the terminal components of glycoconjugates, are poorly understood in sEV. METHODS: Sialic acid levels on sEV from plasma and bladder cancer cells were determined by ELISA and lectin blotting. Effects of sialylation on sEV uptake were determined by flow cytometry. Vesicular glycoproteins bearing sialic acids responsible for sEV uptake was identified by proteomics and density gradient centrifugation, and their site-specific sialylation functions were assayed by N-glycosylation site mutation. Effects of integrin ß1 bearing sialic acids on the pro-metastatic function of sEV in vivo were explored using Balb/c nu/nu mice. RESULTS: (1) Increased sialic acid levels were observed in sEV from malignant bladder cancer cells. (2) Elimination of sialic acids on sEV impaired sEV uptake by recipient cells. (3) Vesicular integrin ß1 bearing sialic acids was identified to play a key role in sEV uptake. (4) Desialylation of the hybrid domain of vesicular integrin ß1 inhibited its binding to matrix fibronectin, and reduced sEV entry into recipient cells. (5) Sialylation on integrin ß1 affected pro-metastatic function of sEV in Balb/c nu/nu mice. CONCLUSIONS: Taken together, our findings indicate important functional roles of sialic acids in sEV uptake and reprogramming plasticity of surrounding normal epithelial cells.


Subject(s)
Extracellular Vesicles , Urinary Bladder Neoplasms , Animals , Mice , Extracellular Vesicles/metabolism , Glycoconjugates , Integrin beta1/metabolism , Mammals , N-Acetylneuraminic Acid/metabolism , Sialic Acids/metabolism
20.
Retina ; 44(5): 782-790, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38237083

ABSTRACT

PURPOSE: To evaluate the incidence, associated factors, and outcome of persistent subretinal fluid (SRF) after vitrectomy for macular hole-associated retinal detachment (MHRD). METHODS: A total of 158 eyes from 156 patients with MHRD who achieved macular hole closure after primary vitrectomy were included in the analysis; persistent SRF was defined as the presence of SRF for more than 1 month after first surgery. Preoperative and postoperative parameters were analyzed for their relationship with SRF development. RESULTS: Persistent SRF was observed in 19 eyes (12.0% of 158) postoperatively. Seven eyes (36.8% of 19) with persistent SRF eventually displayed complete absorption during follow-up. Univariate analysis revealed that eyes with persistent SRF were statistically associated with internal limiting membrane inverted flap, duration of symptoms, tamponade (perfluoropropane/silicone oil: 14/5 vs. 35/104, P < 0.001), and MHRD subtype (Type 1/Type 2/Type 3: 15/4/0 vs. 60/40/39, P = 0.003). In multivariate analysis, only internal limiting membrane inverted flap (odds ratio, 15.778, 95% confidence interval, 3.170-78.523; P = 0.001) was positively associated with persistent SRF. There were no significant differences in best-corrected visual acuity improvement ( P = 0.425) between the SRF involved foveal and without involved foveal groups and no significant differences between the SRF complete absorption and incomplete absorption groups. CONCLUSION: Absorption of persistent SRF may be more difficult in MHRD eyes than in ordinary rhegmatogenous retinal detachment eyes. The internal limiting membrane inverted flap in MHRD was associated with a greater likelihood of persistent SRF. The location and incomplete absorption of persistent SRF did not seem to be associated with the final visual outcome.


Subject(s)
Endotamponade , Retinal Detachment , Retinal Perforations , Subretinal Fluid , Tomography, Optical Coherence , Visual Acuity , Vitrectomy , Humans , Vitrectomy/methods , Retinal Detachment/surgery , Retinal Detachment/diagnosis , Retinal Detachment/etiology , Male , Female , Retinal Perforations/surgery , Retinal Perforations/diagnosis , Retinal Perforations/etiology , Retrospective Studies , Aged , Middle Aged , Endotamponade/methods , Tomography, Optical Coherence/methods , Postoperative Complications , Follow-Up Studies , Fluorocarbons/administration & dosage , Incidence
SELECTION OF CITATIONS
SEARCH DETAIL