Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 112
1.
J Speech Lang Hear Res ; : 1-9, 2024 May 20.
Article En | MEDLINE | ID: mdl-38768072

PURPOSE: This study explored the facilitatory effect of visual articulatory cues on the identification of Mandarin lexical tones by children with cochlear implants (CIs) in both quiet and noisy environments. It also explored whether early implantation is associated with better use of visual cues in tonal identification. METHOD: Participants included 106 children with CIs and 100 normal-hearing (NH) controls. A tonal identification task was employed using a two-alternative forced-choice picture-pointing paradigm. Participants' tonal identification accuracies were compared between audio-only (AO) and audiovisual (AV) modalities. Correlations between implantation ages and visual benefits (accuracy differences between AO and AV modalities) were also examined. RESULTS: Children with CIs demonstrated an improved identification accuracy from AO to AV modalities in the noisy environment. Additionally, earlier implantation was significantly correlated with a greater visual benefit in noise. CONCLUSIONS: These findings indicated that children with CIs benefited from visual cues on tonal identification in noise, and early implantation enhanced the visual benefit. These results thus have practical implications on tonal perception interventions for Mandarin-speaking children with CIs.

2.
Article En | MEDLINE | ID: mdl-38740543

BACKGROUND AND AIM: Extraintestinal manifestations (EIMs) pose a significant threat in inflammatory bowel disease (IBD) patients. Vedolizumab (VDZ) primarily affects the gastrointestinal tract. However, its impact on EIMs remains uncertain. Therefore, we conducted this meta-analysis to examine the effects of VDZ on EIMs during treatment. METHODS: Relevant studies were identified by conducting thorough searches across electronic databases, including PubMed, Ovid Embase, Medline, and Cochrane CENTRAL. Primary outcomes focused on the proportion of patients with resolution for pre-existing EIMs in IBD patients receiving VDZ. Secondary outcomes included the proportion of patients with EIM exacerbations and new onset EIMs during VDZ treatment. RESULTS: Our meta-analysis encompassed 21 studies. The proportion of patients with resolution of pre-existing EIMs in VDZ-treated IBD patients was 39% (150/386; 95% confidence interval [CI] 0.31-0.48). The proportion of patients with EIM exacerbations occurred at a rate of 28% (113/376; 95% CI 0.05-0.50), while new onset EIMs had a rate of 15% (397/2541; 95% CI 0.10-0.20). Subgroup analysis revealed a 40% (136/337) proportion of patients with resolution for articular-related EIMs and a 50% (9/18) rate for erythema nodosum. Exacerbation rates for arthritis/arthralgia, erythema nodosum/pyoderma gangrenosum, and aphthous stomatitis during VDZ use were 28% (102/328), 18% (7/38), and 11% (3/28), respectively. The incidence rate of newly developed EIMs during treatment was 11% (564/4839) for articular-related EIMs, with other EIMs below 2%. CONCLUSION: VDZ demonstrates efficacy in skin-related EIMs like erythema nodosum and joint-related EIMs including arthritis, arthralgia, spondyloarthritis, and peripheral joint diseases. Some joint and skin-related EIMs may experience exacerbation during VDZ therapy.

3.
Animals (Basel) ; 14(8)2024 Apr 17.
Article En | MEDLINE | ID: mdl-38672347

The aim of this study was to evaluate the effects of a high-energy low-protein (HELP) diet on lipid metabolism and inflammation in the liver and abdominal adipose tissue (AAT) of laying hens. A total of 200 Roman laying hens (120 days old) were randomly divided into two experimental groups: negative control group (NC group) and HELP group, with 100 hens per group. The chickens in the NC group were fed with a basic diet, whereas those in the HELP group were given a HELP diet. Blood, liver, and AAT samples were collected from 20 chickens per group at each experimental time point (30, 60, and 90 d). The morphological and histological changes in the liver and AAT were observed, and the level of serum biochemical indicators and the relative expression abundance of key related genes were determined. The results showed that on day 90, the chickens in the HELP group developed hepatic steatosis and inflammation. However, the diameter of the adipocytes of AAT in the HELP group was significantly larger than that of the NC group. Furthermore, the results showed that the extension of the feeding time significantly increased the lipid contents, lipid deposition, inflammatory parameters, and peroxide levels in the HELP group compared with the NC group, whereas the antioxidant parameters decreased significantly. The mRNA expression levels of genes related to lipid synthesis such as fatty acid synthase (FASN), stearoyl-coA desaturase (SCD), fatty acid binding protein 4 (FABP4), and peroxisome proliferator-activated receptor gamma (PPARγ) increased significantly in the liver and AAT of the HELP group, whereas genes related to lipid catabolism decreased significantly in the liver. In addition, the expression of genes related to lipid transport and adipokine synthesis decreased significantly in the AAT, whereas in the HELP group, the expression levels of pro-inflammatory parameters such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1ß) increased significantly in the liver and AAT. Conversely, the expression level of the anti-inflammatory parameter interleukin-10 (IL-10) decreased significantly in the liver. The results indicated that the HELP diet induced lipid peroxidation and inflammation in the liver and AAT of the laying hens. Hence, these results suggest that chicken AAT may be involved in the development of fatty liver.

4.
BMC Genomics ; 25(1): 400, 2024 Apr 24.
Article En | MEDLINE | ID: mdl-38658807

BACKGROUND: Skeletal muscle is composed of muscle fibers with different physiological characteristics, which plays an important role in regulating skeletal muscle metabolism, movement and body homeostasis. The type of skeletal muscle fiber directly affects meat quality. However, the transcriptome and gene interactions between different types of muscle fibers are not well understood. RESULTS: In this paper, we selected 180-days-old Large White pigs and found that longissimus dorsi (LD) muscle was dominated by fast-fermenting myofibrils and soleus (SOL) muscle was dominated by slow-oxidizing myofibrils by frozen sections and related mRNA and protein assays. Here, we selected LD muscle and SOL muscle for transcriptomic sequencing, and identified 312 differentially expressed mRNA (DEmRs), 30 differentially expressed miRNA (DEmiRs), 183 differentially expressed lncRNA (DElRs), and 3417 differentially expressed circRNA (DEcRs). The ceRNA network included ssc-miR-378, ssc-miR-378b-3p, ssc-miR-24-3p, XR_308817, XR_308823, SMIM8, MAVS and FOS as multiple core nodes that play important roles in muscle development. Moreover, we found that different members of the miR-10 family expressed differently in oxidized and glycolytic muscle fibers, among which miR-10a-5p was highly expressed in glycolytic muscle fibers (LD) and could target MYBPH gene mRNA. Therefore, we speculate that miR-10a-5p may be involved in the transformation of muscle fiber types by targeting the MYHBP gene. In addition, PPI analysis of differentially expressed mRNA genes showed that ACTC1, ACTG2 and ACTN2 gene had the highest node degree, suggesting that this gene may play a key role in the regulatory network of muscle fiber type determination. CONCLUSIONS: We can conclude that these genes play a key role in regulating muscle fiber type transformation. Our study provides transcriptomic profiles and ceRNA interaction networks for different muscle fiber types in pigs, providing reference for the transformation of pig muscle fiber types and the improvement of meat quality.


Gene Regulatory Networks , Animals , Swine , MicroRNAs/genetics , MicroRNAs/metabolism , Gene Expression Profiling , Muscle Fibers, Skeletal/metabolism , Muscle, Skeletal/metabolism , Transcriptome , RNA, Messenger/genetics , RNA, Messenger/metabolism
5.
Fitoterapia ; 175: 105946, 2024 Jun.
Article En | MEDLINE | ID: mdl-38575087

Four compounds (1-4) featuring with an L-rhodinose and spiroketal, possess uncommon continuous hydroxy groups in the macrolide skeleton, and a dichloro-diketopiperazine (5) were isolated from a marine derived Micromonospora sp. FIMYZ51. The determination of the relative and absolute configurations of all isolates was achieved by extensive spectroscopic analyses, single-crystal X-ray diffraction analysis, and ECD calculations. According to structural characteristic and genomic sequences, a plausible biosynthetic pathway for compound 1-4 was proposed and a spirocyclase was inferred to be responsible for the formation of the rare spirocyclic moiety. Compounds 1-4 exhibited potent antifungal activities which is equal to itraconazole against Aspergillus niger. Compounds 1-5 exhibited different degree of inhibitory activities against opportunistic pathogenic bacteria of endocarditis (Micrococcus luteus) with MIC values ranging from 0.0625 µg/mL to 32 µg/mL. Compounds 2 and 3 showed moderate cytotoxicity against drug-resistant tumor cell lines (Namalwa and U266). The result not only provides active lead-compounds, but also reveal the potential of the spirocyclase gene resources from Micromonospora sp., which highlights the promising potential of the strain for biomedical applications.


Diketopiperazines , Macrolides , Micromonospora , Spiro Compounds , Molecular Structure , Diketopiperazines/pharmacology , Diketopiperazines/isolation & purification , Diketopiperazines/chemistry , Spiro Compounds/pharmacology , Spiro Compounds/isolation & purification , Spiro Compounds/chemistry , Cell Line, Tumor , Humans , Macrolides/pharmacology , Macrolides/isolation & purification , Macrolides/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/chemistry , Antifungal Agents/pharmacology , Antifungal Agents/isolation & purification , Antifungal Agents/chemistry , Microbial Sensitivity Tests , China , Antineoplastic Agents/pharmacology , Antineoplastic Agents/isolation & purification , Antineoplastic Agents/chemistry , Furans
6.
ACS Macro Lett ; 13(5): 550-557, 2024 May 21.
Article En | MEDLINE | ID: mdl-38634712

Highly ordered, network-nanostructured polymers offer compelling geometric features and application potential. However, their practical utilization is hampered by the restricted accessibility. Here, we address this challenge using commercial Pluronic surfactants with a straightforward modification of tethering polymerizable groups. By leveraging lyotropic self-assembly, we achieve facile production of double-gyroid mesophases, which are subsequently solidified via photoinduced cross-linking. The exceptionally ordered periodicities of Ia3d symmetry in the photocured polymers are unambiguously confirmed by synchrotron small-angle X-ray scattering (SAXS), which can capture single-crystal-like diffraction patterns. Electron density maps reconstructed from SAXS data complemented by transmission electron microscopy analysis further elucidate the real-space gyroid assemblies. Intriguingly, by tuning the cross-linking through thiol-acrylate chemistry, the mechanical properties of the polymer are modulated without compromising the integrity of Ia3d assemblies. The 3-D percolating gyroid nanochannels demonstrate an ionic conductivity that surpasses that of disordered structures, offering promising prospects for scalable fabrication.

7.
Cancer Cell ; 42(4): 535-551.e8, 2024 Apr 08.
Article En | MEDLINE | ID: mdl-38593780

Inter- and intra-tumor heterogeneity is a major hurdle in primary liver cancer (PLC) precision therapy. Here, we establish a PLC biobank, consisting of 399 tumor organoids derived from 144 patients, which recapitulates histopathology and genomic landscape of parental tumors, and is reliable for drug sensitivity screening, as evidenced by both in vivo models and patient response. Integrative analysis dissects PLC heterogeneity, regarding genomic/transcriptomic characteristics and sensitivity to seven clinically relevant drugs, as well as clinical associations. Pharmacogenomic analysis identifies and validates multi-gene expression signatures predicting drug response for better patient stratification. Furthermore, we reveal c-Jun as a major mediator of lenvatinib resistance through JNK and ß-catenin signaling. A compound (PKUF-01) comprising moieties of lenvatinib and veratramine (c-Jun inhibitor) is synthesized and screened, exhibiting a marked synergistic effect. Together, our study characterizes the landscape of PLC heterogeneity, develops predictive biomarker panels, and identifies a lenvatinib-resistant mechanism for combination therapy.


Biological Specimen Banks , Liver Neoplasms , Phenylurea Compounds , Quinolines , Humans , Pharmacogenetics , Precision Medicine , Liver Neoplasms/drug therapy , Liver Neoplasms/genetics , Liver Neoplasms/pathology , Organoids
8.
Curr Issues Mol Biol ; 46(3): 2514-2527, 2024 Mar 15.
Article En | MEDLINE | ID: mdl-38534775

There has been debate about whether individuals with different color phenotypes should have different taxonomic status. In order to determine whether the different color phenotypes of Nedyopus patrioticus require separate taxonomic status or are simply synonyms, here, the complete mitochondrial genomes (mitogenomes) of two different colored N. patrioticus, i.e., red N. patrioticus and white N. patrioticus, are presented. The two mitogenomes were 15,781 bp and 15,798 bp in length, respectively. Each mitogenome contained 13 PCGs, 19 tRNAs, 2 rRNAs, and 1 CR, with a lack of trnI, trnL2, and trnV compared to other Polydesmida species. All genes were located on a single strand in two mitogenomes. Mitochondrial DNA analyses revealed that red N. patrioticus and white N. patrioticus did not show clear evolutionary differences. Furthermore, no significant divergence was discovered by means of base composition analysis. As a result, we suggest that white N. patrioticus might be regarded as a synonym for red N. patrioticus. The current findings confirmed the existence of color polymorphism in N. patrioticus, which provides exciting possibilities for future research. It is necessary to apply a combination of molecular and morphological methods in the taxonomy of millipedes.

9.
Talanta ; 273: 125872, 2024 Jun 01.
Article En | MEDLINE | ID: mdl-38471421

Gene methylation-related enzymes (GMREs) are disfunction and aberrantly expressed in a variety of cancers, such as lung, gastric, and pancreatic cancers and have important implications for human health. Therefore,it is critical for early diagnosis and therapy of tumor to develop strategies that allow rapid and sensitive quantitative and qualitative detection of GMREs. With the development of modern analytical techniques and the application of various biosensors, there are numerous methods have been developed for analysis of GMREs. Therefore, this paper provides a systematic review of the strategies for level and activity assay of various GMREs including methyltransferases and demethylase. The detection methods mainly involve immunohistochemistry, colorimetry, fluorescence, chemiluminescence, electrochemistry, etc. Then, this review also addresses the coordinated role of various detection probes, novel nanomaterials, and signal amplification methods. The aim is to highlight potential challenges in the present field, to expand the analytical application of GMREs detection strategies, and to meet the urgent need for future disease diagnosis and intervention.


Biosensing Techniques , Neoplasms , Humans , DNA Methylation , RNA Methylation , DNA/genetics , Biosensing Techniques/methods , Neoplasms/genetics
10.
Clin Oral Investig ; 28(4): 222, 2024 Mar 19.
Article En | MEDLINE | ID: mdl-38499947

OBJECTIVES: To compare the effectiveness of caries arrest by micro-operative treatment (sealing) to operative treatment (flowable resin composite restoration) through a 2-year randomized controlled clinical trial. MATERIALS AND METHODS: A prospective randomized controlled trial was conducted among 7-9-year-old children. At baseline, 630 subjects were screened and 92 children who had at least one carious lesion classified as ICDAS 3 on the pit and fissure of first permanent molar were included. Then they were randomly assigned to the sealant group (73 lesions) and the flowable resin composite group (76 lesions) to receive the corresponding intervention. Lesions status in each group was evaluated every 6 months up to 24 months. Clinical progression of dental caries and materials retention were the outcomes used for group comparisons at p-value < 0.05. RESULTS: After 24 months, three lesions (4.1%) in the sealant group clinically progressed to dentin caries. No lesion in the flowable composite group was observed a progression. The results of Life-table survival analysis show that the cumulative caries arrest rate had no statistically significant difference between the two groups (p = 0.075). However, the cumulative retention rate was 57.5% in the sealant group and 92.1% in the flowable composite group, with significant differences (p < 0.001). The multilevel mixed model showed the sealant had higher risk of retention failure than the flowable composite (OR = 8.66, p < 0.001), while tooth position did not influence material retention (p = 0.083). In addition, the results of Fisher Exact test show that dentin lesions had more retention failure than enamel lesions in the sealant group (p = 0.026). CONCLUSION: Although sealing microcavitated carious lesions of the first permanent molar achieved lower retention rate than resin composite restoration, both sealing and restoration effectively arrested caries progression for two years. CLINICAL RELEVANCE: To preserving dental structure and delaying or eliminating the need for operative procedures, microcavitated carious lesion can be arrested by sealing. TRIAL REGISTRATION: Registered at http://www.chictr.org.cn ; Feb 15th, 2020; No. ChiCTR2000029862.


Dental Caries , Child , Humans , Dental Caries/surgery , Dental Caries/pathology , Pit and Fissure Sealants/therapeutic use , Dental Caries Susceptibility , Prospective Studies , Molar/pathology
11.
Front Neurorobot ; 18: 1355857, 2024.
Article En | MEDLINE | ID: mdl-38362125

Introduction: Acupoint localization is integral to Traditional Chinese Medicine (TCM) acupuncture diagnosis and treatment. Employing intelligent detection models for recognizing facial acupoints can substantially enhance localization accuracy. Methods: This study introduces an advancement in the YOLOv8-pose keypoint detection algorithm, tailored for facial acupoints, and named YOLOv8-ACU. This model enhances acupoint feature extraction by integrating ECA attention, replaces the original neck module with a lighter Slim-neck module, and improves the loss function for GIoU. Results: The YOLOv8-ACU model achieves impressive accuracy, with an mAP@0.5 of 97.5% and an mAP@0.5-0.95 of 76.9% on our self-constructed datasets. It also marks a reduction in model parameters by 0.44M, model size by 0.82 MB, and GFLOPs by 9.3%. Discussion: With its enhanced recognition accuracy and efficiency, along with good generalization ability, YOLOv8-ACU provides significant reference value for facial acupoint localization and detection. This is particularly beneficial for Chinese medicine practitioners engaged in facial acupoint research and intelligent detection.

12.
Genes (Basel) ; 15(2)2024 Feb 18.
Article En | MEDLINE | ID: mdl-38397243

This study presents the complete mitochondrial genome (mitogenome) of Litostrophus scaber, which is the first mitogenome of the genus Litostrophus. The mitogenome is a circular molecule with a length of 15,081 bp. The proportion of adenine and thymine (A + T) was 69.25%. The gene ND4L used TGA as the initiation codon, while the other PCGs utilized ATN (A, T, G, C) as the initiation codons. More than half of the PCGs used T as an incomplete termination codon. The transcription direction of the L. scaber mitogenome matched Spirobolus bungii, in contrast to most millipedes. Novel rearrangements were found in the L. scaber mitogenome: trnQ -trnC and trnL1- trnP underwent short-distance translocations and the gene block rrnS-rrnL-ND1 moved to a position between ND4 and ND5, resulting in the formation of a novel gene order. The phylogenetic analysis showed that L. scaber is most closely related to S. bungii, followed by Narceus magnum. These findings enhance our understanding of the rearrangement and evolution of Diplopoda mitogenomes.


Arthropods , Genome, Mitochondrial , Animals , Genome, Mitochondrial/genetics , Phylogeny , Base Composition , Arthropods/genetics , Codon, Initiator
13.
Angew Chem Int Ed Engl ; 63(16): e202400952, 2024 Apr 15.
Article En | MEDLINE | ID: mdl-38372593

Cu-based catalysts have been identified as the most promising candidates for generation of C2+ products in electrochemical CO2 reduction reaction. Defect engineering in catalysts is a widely employed strategy for promoting C-C coupling on Cu. However, comprehensive understanding of defect structure-to-activity relationship has not been obtained. In this study, controllable defects generation is achieved, which leads to a series of Cu-based catalysts with various phase mixing degrees. It is observed that the Faradaic efficiency toward C2+ products increases with the phase mixing degree, reaching 81 % at maximum. In situ infrared absorption spectroscopy reveals that the catalysts with higher phase mixing degree tend to form *CO more easily and possess higher retention of *CO under high overpotential window, thereby promoting C-C coupling. This work sheds new light on the relationship between defects and C-C coupling, and the rational developed of more advanced Cu-base catalysts.

14.
Mar Drugs ; 22(2)2024 Jan 24.
Article En | MEDLINE | ID: mdl-38393028

Oxidative stress, which damages cellular components and causes mitochondrial dysfunction, occurs in a variety of human diseases, including neurological disorders. The clearance of damaged mitochondria via mitophagy maintains the normal function of mitochondria and facilitates cell survival. Astaxanthin is an antioxidant known to have neuroprotective effects, but the underlying mechanisms remain unclear. This study demonstrated that astaxanthin inhibited H2O2-induced apoptosis in SH-SY5Y cells by ameliorating mitochondrial damage and enhancing cell survival. H2O2 treatment significantly reduced the levels of activated Akt and mTOR and induced mitophagy, while pretreatment with astaxanthin prevented H2O2-induced inhibition of Akt and mTOR and attenuated H2O2-induced mitophagy. Moreover, the inhibition of Akt attenuated the protective effect of astaxanthin against H2O2-induced cytotoxicity. Taken together, astaxanthin might inhibit H2O2-induced apoptosis by protecting mitochondrial function and reducing mitophagy. The results also indicate that the Akt/mTOR signaling pathway was critical for the protection of astaxanthin against H2O2-induced cytotoxicity. The results from the present study suggest that astaxanthin can reduce neuronal oxidative injury and may have the potential to be used for preventing neurotoxicity associated with neurodegenerative diseases.


Neuroblastoma , Proto-Oncogene Proteins c-akt , Humans , Proto-Oncogene Proteins c-akt/metabolism , Hydrogen Peroxide/toxicity , Mitophagy , Neuroblastoma/drug therapy , Apoptosis , Oxidative Stress , TOR Serine-Threonine Kinases/metabolism , Cell Line, Tumor , Reactive Oxygen Species/metabolism , Xanthophylls
16.
Nucleic Acids Res ; 52(8): 4215-4233, 2024 May 08.
Article En | MEDLINE | ID: mdl-38364861

The limited regenerative capacity of the human heart contributes to high morbidity and mortality worldwide. In contrast, zebrafish exhibit robust regenerative capacity, providing a powerful model for studying how to overcome intrinsic epigenetic barriers maintaining cardiac homeostasis and initiate regeneration. Here, we present a comprehensive analysis of the histone modifications H3K4me1, H3K4me3, H3K27me3 and H3K27ac during various stages of zebrafish heart regeneration. We found a vast gain of repressive chromatin marks one day after myocardial injury, followed by the acquisition of active chromatin characteristics on day four and a transition to a repressive state on day 14, and identified distinct transcription factor ensembles associated with these events. The rapid transcriptional response involves the engagement of super-enhancers at genes implicated in extracellular matrix reorganization and TOR signaling, while H3K4me3 breadth highly correlates with transcriptional activity and dynamic changes at genes involved in proteolysis, cell cycle activity, and cell differentiation. Using loss- and gain-of-function approaches, we identified transcription factors in cardiomyocytes and endothelial cells influencing cardiomyocyte dedifferentiation or proliferation. Finally, we detected significant evolutionary conservation between regulatory regions that drive zebrafish and neonatal mouse heart regeneration, suggesting that reactivating transcriptional and epigenetic networks converging on these regulatory elements might unlock the regenerative potential of adult human hearts.


Chromatin , Gene Regulatory Networks , Heart , Histones , Myocytes, Cardiac , Regeneration , Zebrafish , Zebrafish/genetics , Animals , Regeneration/genetics , Chromatin/metabolism , Chromatin/genetics , Histones/metabolism , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/cytology , Mice , Humans , Epigenesis, Genetic , Transcription Factors/metabolism , Transcription Factors/genetics , Histone Code , Cell Differentiation/genetics
17.
J Am Chem Soc ; 146(3): 1935-1945, 2024 Jan 24.
Article En | MEDLINE | ID: mdl-38191290

The reaction mechanism of CO2 electroreduction on oxide-derived copper has not yet been unraveled even though high C2+ Faradaic efficiencies are commonly observed on these surfaces. In this study, we aim to explore the effects of copper anodization on the adsorption of various CO2RR intermediates using in situ surface-enhanced infrared absorption spectroscopy (SEIRAS) on metallic and mildly anodized copper thin films. The in situ SEIRAS results show that the preoxidation process can significantly improve the overall CO2 reduction activity by (1) enhancing CO2 activation, (2) increasing CO uptake, and (3) promoting C-C coupling. First, the strong *COO- redshift indicates that the preoxidation process significantly enhances the first elementary step of CO2 adsorption and activation. The rapid uptake of adsorbed *COatop also illustrates how a high *CO coverage can be achieved in oxide-derived copper electrocatalysts. Finally, for the first time, we observed the formation of the *COCHO dimer on the anodized copper thin film. Using DFT calculations, we show how the presence of subsurface oxygen within the Cu lattice can improve the thermodynamics of C2 product formation via the coupling of adsorbed *CO and *CHO intermediates. This study advances our understanding of the role of surface and subsurface conditions in improving the catalytic reaction kinetics and product selectivity of CO2 reduction.

18.
Nat Commun ; 15(1): 1, 2024 01 02.
Article En | MEDLINE | ID: mdl-38169466

Toll-like receptor 9 (TLR9) recognizes self-DNA and plays intricate roles in systemic lupus erythematosus (SLE). However, the molecular mechanism regulating the endosomal TLR9 response is incompletely understood. Here, we report that palmitoyl-protein thioesterase 1 (PPT1) regulates systemic autoimmunity by removing S-palmitoylation from TLR9 in lysosomes. PPT1 promotes the secretion of IFNα by plasmacytoid dendritic cells (pDCs) and TNF by macrophages. Genetic deficiency in or chemical inhibition of PPT1 reduces anti-nuclear antibody levels and attenuates nephritis in B6.Sle1yaa mice. In healthy volunteers and patients with SLE, the PPT1 inhibitor, HDSF, reduces IFNα production ex vivo. Mechanistically, biochemical and mass spectrometry analyses demonstrated that TLR9 is S-palmitoylated at C258 and C265. Moreover, the protein acyltransferase, DHHC3, palmitoylates TLR9 in the Golgi, and regulates TLR9 trafficking to endosomes. Subsequent depalmitoylation by PPT1 facilitates the release of TLR9 from UNC93B1. Our results reveal a posttranslational modification cycle that controls TLR9 response and autoimmunity.


Autoimmunity , Lupus Erythematosus, Systemic , Humans , Animals , Mice , Toll-Like Receptor 9/metabolism , Lipoylation , Signal Transduction , Dendritic Cells
19.
Nat Commun ; 15(1): 937, 2024 Jan 31.
Article En | MEDLINE | ID: mdl-38297033

Malaria poses an enormous threat to human health. With ever increasing resistance to currently deployed drugs, breakthrough compounds with novel mechanisms of action are urgently needed. Here, we explore pyrimidine-based sulfonamides as a new low molecular weight inhibitor class with drug-like physical parameters and a synthetically accessible scaffold. We show that the exemplar, OSM-S-106, has potent activity against parasite cultures, low mammalian cell toxicity and low propensity for resistance development. In vitro evolution of resistance using a slow ramp-up approach pointed to the Plasmodium falciparum cytoplasmic asparaginyl-tRNA synthetase (PfAsnRS) as the target, consistent with our finding that OSM-S-106 inhibits protein translation and activates the amino acid starvation response. Targeted mass spectrometry confirms that OSM-S-106 is a pro-inhibitor and that inhibition of PfAsnRS occurs via enzyme-mediated production of an Asn-OSM-S-106 adduct. Human AsnRS is much less susceptible to this reaction hijacking mechanism. X-ray crystallographic studies of human AsnRS in complex with inhibitor adducts and docking of pro-inhibitors into a model of Asn-tRNA-bound PfAsnRS provide insights into the structure-activity relationship and the selectivity mechanism.


Antimalarials , Aspartate-tRNA Ligase , Animals , Humans , Plasmodium falciparum/genetics , Asparagine/metabolism , Aspartate-tRNA Ligase/genetics , RNA, Transfer, Amino Acyl/metabolism , Antimalarials/pharmacology , Mammals/genetics
20.
Angew Chem Int Ed Engl ; 63(9): e202313858, 2024 Feb 26.
Article En | MEDLINE | ID: mdl-38185801

Catalysts involving post-transition metals have shown almost invincible performance on generating formate in electrochemical CO2 reduction reaction (CO2 RR). Conversely, Cu without post-transition metals has struggled to achieve comparable activity. In this study, a sulfur (S)-doped-copper (Cu)-based catalyst is developed, exhibiting excellent performance in formate generation with a maximum Faradaic efficiency of 92 % and a partial current density of 321 mA cm-2 . Ex situ structural elucidations reveal the presence of abundant grain boundaries and high retention of S-S bonds from the covellite phase during CO2 RR. Furthermore, thermodynamic calculations demonstrate that S-S bonds can moderate the binding energies with various intermediates, further improving the activity of the formate pathway. This work is significant in modifying a low-cost catalyst (Cu) with a non-metallic element (S) to achieve comparable performance to mainstream catalysts for formate generation in industrial grade.

...