Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 991
Filter
1.
Nat Commun ; 15(1): 3894, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38719837

ABSTRACT

The F-box domain is a highly conserved structural motif that defines the largest class of ubiquitin ligases, Skp1/Cullin1/F-box protein (SCF) complexes. The only known function of the F-box motif is to form the protein interaction surface with Skp1. Here we show that the F-box domain can function as an environmental sensor. We demonstrate that the F-box domain of Met30 is a cadmium sensor that blocks the activity of the SCFMet30 ubiquitin ligase during cadmium stress. Several highly conserved cysteine residues within the Met30 F-box contribute to binding of cadmium with a KD of 8 µM. Binding induces a conformational change that allows for Met30 autoubiquitylation, which in turn leads to recruitment of the segregase Cdc48/p97/VCP followed by active SCFMet30 disassembly. The resulting inactivation of SCFMet30 protects cells from cadmium stress. Our results show that F-box domains participate in regulation of SCF ligases beyond formation of the Skp1 binding interface.


Subject(s)
Cadmium , Protein Binding , SKP Cullin F-Box Protein Ligases , Cadmium/metabolism , SKP Cullin F-Box Protein Ligases/metabolism , SKP Cullin F-Box Protein Ligases/genetics , Valosin Containing Protein/metabolism , Valosin Containing Protein/genetics , Saccharomyces cerevisiae/metabolism , Stress, Physiological , F-Box Proteins/metabolism , F-Box Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae Proteins/genetics , Ubiquitination , Protein Domains , Humans , S-Phase Kinase-Associated Proteins/metabolism , S-Phase Kinase-Associated Proteins/genetics , Cell Cycle Proteins/metabolism , Cell Cycle Proteins/genetics
2.
Viruses ; 16(5)2024 05 11.
Article in English | MEDLINE | ID: mdl-38793644

ABSTRACT

Neutralizing antibodies targeting the spike (S) protein of SARS-CoV-2, elicited either by natural infection or vaccination, are crucial for protection against the virus. Nonetheless, the emergence of viral escape mutants presents ongoing challenges by contributing to breakthrough infections. To define the evolution trajectory of SARS-CoV-2 within the immune population, we co-incubated replication-competent rVSV/SARS-CoV-2/GFP chimeric viruses with sera from COVID-19 convalescents. Our findings revealed that the E484D mutation contributes to increased viral resistant against both convalescent and vaccinated sera, while the L1265R/H1271Y double mutation enhanced viral infectivity in 293T-hACE2 and Vero cells. These findings suggest that under the selective pressure of polyclonal antibodies, SARS-CoV-2 has the potential to accumulate mutations that facilitate either immune evasion or greater infectivity, facilitating its adaption to neutralizing antibody responses. Although the mutations identified in this study currently exhibit low prevalence in the circulating SARS-CoV-2 populations, the continuous and meticulous surveillance of viral mutations remains crucial. Moreover, there is an urgent necessity to develop next-generation antibody therapeutics and vaccines that target diverse, less mutation-prone antigenic sites to ensure more comprehensive and durable immune protection against SARS-CoV-2.


Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , COVID-19 , Mutation , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , SARS-CoV-2/immunology , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Humans , COVID-19/immunology , COVID-19/virology , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/blood , Antibodies, Viral/immunology , Antibodies, Viral/blood , Animals , Chlorocebus aethiops , Vero Cells , Immune Evasion , HEK293 Cells
3.
J Craniofac Surg ; 2024 May 17.
Article in English | MEDLINE | ID: mdl-38758565

ABSTRACT

OBJECTIVE: To study the efficacy of ultrasound-guided parasternal block (US-PSI) in pediatric patients undergoing auricular reconstruction surgery. METHODS: For this study, the authors recruited 60 children between the ages of 5 and 12 years who underwent auricular reconstruction with autologous costal cartilage (ACC) to correct microtia. They were randomized to receive either ultrasound-guided modified parasternal block or periprostatic local infiltration anesthesia (PLIA), with 30 cases in each group. Ultrasound-guided parasternal block was administered following anesthesia induction, whereas PLIA was administered after ACC harvest. Lastly, following surgery, all children were provided with patient-controlled intravenous analgesia with sufentanil, and the numeric pain rating scale (NRS) was used to assess the intensity of pain. Our primary outcomes were the resting NRS pain scores and the NRS scores upon coughing at 1, 6, 12, 24, and 48 hours postsurgery. Sufentanil consumption within the first 24 hours of surgery, the mean duration to first ambulation, and the usage of rescue analgesics were our secondary outcomes. The authors also recorded the occurrence of undesirable side effects as well as more serious side effects like pneumothorax. RESULTS: Pediatric patients who were administered US-PSI showed significantly reduced NRS chest pain scores at 6 and 12 hours postsurgery compared to those who received PLIA (P<0.05). In addition, sufentanil consumption within the first 24 hours postsurgery, duration to first ambulation, and use of rescue analgesics were significantly lower among patients in the US-PSI group when compared to those in the PLIA group (P<0.05). CONCLUSIONS: This study found that US-PSI was a highly efficacious and safe technique for postsurgical analgesia following auricular reconstruction with ACC in pediatric patients. LEVEL OF EVIDENCE: Level II, therapeutic study.

4.
Nat Prod Res ; : 1-7, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38771014

ABSTRACT

An undescribed dammarane triterpenoid saponin Cypaliuruside F was isolated from the leaves of Cyclocarya paliurus in our preliminary study. The MTT assay, flow cytometry, cell scratch, and DAPI staining were used to detect the antitumor effects of Cypaliuruside F on HepG2 cells. Subsequently, network pharmacology and molecular docking analysis were used to analyse the key targets of Cypaliuruside F against HCC. In addition, a Western blot was performed to determine the effects of Cypaliuruside F on the expression of key proteins in HepG2 cells. The experimental results indicated that the damarane triterpenoid saponin Cypaliuruside F from Cyclocarya paliurus inhibits the proliferation of HepG2 cells by inducing apoptosis and cell cycle arrest. These changes may promote the apoptosis of HepG2 cells by inhibiting the expression of mTOR, STAT3, and Bcl-2 while activating Bax.

6.
Redox Biol ; 73: 103183, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38759418

ABSTRACT

AIMS: Vascular calcification is strongly linked to the development of major adverse cardiovascular events, but effective treatments are lacking. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are an emerging category of oral hypoglycemic drugs that have displayed marked effects on metabolic and cardiovascular diseases, including recently reported vascular medial calcification. However, the roles and underlying mechanisms of SGLT2 inhibitors in vascular calcification have not been fully elucidated. Thus, we aimed to further determine whether SGLT2 inhibitors protect against vascular calcification and to investigate the mechanisms involved. METHODS AND RESULTS: A computed tomography angiography investigation of coronary arteries from 1554 patients with type 2 diabetes revealed that SGLT2 inhibitor use was correlated with a lower Agatston calcification score. In the vitamin D3 overdose, 5/6 nephrectomy chronic kidney disease-induced medial calcification and Western diet-induced atherosclerotic intimal calcification models, dapagliflozin (DAPA) substantially alleviated vascular calcification in the aorta. Furthermore, we showed that DAPA reduced vascular calcification via Runx2-dependent osteogenic transdifferentiation in vascular smooth muscle cells (VSMCs). Transcriptome profiling revealed that thioredoxin domain containing 5 (TXNDC5) was involved in the attenuation of vascular calcification by DAPA. Rescue experiments showed that DAPA-induced TXNDC5 downregulation in VSMCs blocked the protective effect on vascular calcification. Furthermore, TXNDC5 downregulation disrupted protein folding-dependent Runx2 stability and promoted subsequent proteasomal degradation. Moreover, DAPA downregulated TXNDC5 expression via amelioration of oxidative stress and ATF6-dependent endoplasmic reticulum stress. Consistently, the class effects of SGLT2 inhibitors on vascular calcification were validated with empagliflozin in intimal and medial calcification models. CONCLUSIONS: SGLT2 inhibitors ameliorate vascular calcification through blocking endoplasmic reticulum stress-dependent TXNDC5 upregulation and promoting subsequent Runx2 proteasomal degradation, suggesting that SGLT2 inhibitors are potentially beneficial for vascular calcification treatment and prevention.

7.
Eur J Heart Fail ; 2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38606573

ABSTRACT

AIMS: Existing research indicates that patients with heart failure (HF) may have restricted access to guideline-directed medical therapy (GDMT) when their blood pressure (BP) is comparatively low. However, recent clinical trials suggest that HF patients with low BP could still benefit from certain HF medications, which have a minimal impact on BP. This systematic review and meta-analysis was conducted to determine whether this applies to all GDMT. METHODS AND RESULTS: A systematic search of MEDLINE and EMBASE was conducted for studies published from inception to 10 January 2024. Randomized controlled trials were selected if they reported on the longitudinal change of systolic BP (SBP) due to GDMT, or the risks of cardiovascular events in HF patients based on SBP categories. Weighted mean difference (WMD), hazard ratio or relative risk, and corresponding 95% confidence intervals (CI) were pooled for meta-analysis where possible. Data from 20 studies, encompassing information on 84 782 individuals, were analysed. Overall, GDMT is associated with lower SBP (WMD, -2.16; 95% CI -2.86 to -1.46), with no significant difference between baseline low and non-low BP subgroups (interaction p = 0.810). However, SBP of the treatment group increased by 5.8 mmHg from baseline in the low SBP subgroup during follow-up, while it decreased by 4.0 mmHg in the baseline non-low SBP subgroup. GDMT demonstrated similar cardiovascular benefits and risk of hypotension between low and non-low SBP subgroups (interaction p = 0.318 and 0.903, respectively). CONCLUSIONS: Guideline-directed medical therapy is associated with a negligible decrease in SBP, but can provide similar cardiovascular benefits in both low and non-low SBP HF patients, with no significant interaction with SBP as to hypotension. Therefore, GDMT should be initiated and maintained in HF patients with low BP.

9.
Cell Commun Signal ; 22(1): 206, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38566133

ABSTRACT

BACKGROUND: The protein annexin A6 (AnxA6) is involved in numerous membrane-related biological processes including cell migration and invasion by interacting with other proteins. The dysfunction of AnxA6, including protein expression abundance change and imbalance of post-translational modification, is tightly related to multiple cancers. Herein we focus on the biological function of AnxA6 SUMOylation in hepatocellular carcinoma (HCC) progression. METHODS: The modification sites of AnxA6 SUMOylation were identified by LC-MS/MS and amino acid site mutation. AnxA6 expression was assessed by immunohistochemistry and immunofluorescence. HCC cells were induced into the epithelial-mesenchymal transition (EMT)-featured cells by 100 ng/mL 12-O-tetradecanoylphorbol-13-acetate exposure. The ability of cell migration was evaluated under AnxA6 overexpression by transwell assay. The SUMO1 modified AnxA6 proteins were enriched from total cellular proteins by immunoprecipitation with anti-SUMO1 antibody, then the SUMOylated AnxA6 was detected by Western blot using anti-AnxA6 antibody. The nude mouse xenograft and orthotopic hepatoma models were established to determine HCC growth and tumorigenicity in vivo. The HCC patient's overall survival versus AnxA6 expression level was evaluated by the Kaplan-Meier method. RESULTS: Lys579 is a major SUMO1 modification site of AnxA6 in HCC cells, and SUMOylation protects AnxA6 from degradation via the ubiquitin-proteasome pathway. Compared to the wild-type AnxA6, its SUMO site mutant AnxA6K579R leads to disassociation of the binding of AnxA6 with RHOU, subsequently RHOU-mediated p-AKT1ser473 is upregulated to facilitate cell migration and EMT progression in HCC. Moreover, the SENP1 deSUMOylates AnxA6, and AnxA6 expression is negatively correlated with SENP1 protein expression level in HCC tissues, and a high gene expression ratio of ANXA6/SENP1 indicates a poor overall survival of patients. CONCLUSIONS: AnxA6 deSUMOylation contributes to HCC progression and EMT phenotype, and the combination of AnxA6 and SENP1 is a better tumor biomarker for diagnosis of HCC grade malignancy and prognosis.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Animals , Humans , Mice , Annexin A6/genetics , Annexin A6/metabolism , Carcinoma, Hepatocellular/pathology , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation , Chromatography, Liquid , Epithelial-Mesenchymal Transition/genetics , Gene Expression Regulation, Neoplastic , Liver Neoplasms/pathology , Proto-Oncogene Proteins c-akt/metabolism , rho GTP-Binding Proteins/metabolism , Sumoylation , Tandem Mass Spectrometry
10.
Molecules ; 29(7)2024 Apr 05.
Article in English | MEDLINE | ID: mdl-38611920

ABSTRACT

Six new 2α-hydroxy ursane triterpenoids, 3α-cis-p-coumaroyloxy-2α,19α-dihydroxy-12-ursen-28-oic acid (1), 3α-trans-p-coumaroyloxy-2α,19α-dihydroxy-12-ursen-28-oic acid (2), 3α-trans-p-coumaroyloxy-2α-hydroxy-12-ursen-28-oic acid (3), 3ß-trans-p-coumaroyloxy-2α-hydroxy-12,20(30)-ursadien-28-oic acid (4), 3ß-trans-feruloyloxy-2α-hydroxy-12,20(30)-ursadien-28-oic acid (5), and 3α-trans-feruloyloxy-2α-hydroxy-12,20(30)-ursadien-28-oic acid (6), along with eleven known triterpenoids (7-17), were isolated from the leaves of Diospyros digyna. Their chemical structures were elucidated by comprehensive analysis of UV, IR, HRESIMS, and NMR spectra. All the isolated compounds were evaluated for their PTP1B inhibitory activity. 3ß-O-trans-feruloyl-2α-hydroxy-urs-12-en-28-oic acid (13) showed the best inhibition activity with an IC50 value of 10.32 ± 1.21 µM. The molecular docking study found that the binding affinity of compound 13 for PTP1B was comparable to that of oleanolic acid (positive control).


Subject(s)
Diospyros , Triterpenes , Molecular Docking Simulation , Plant Leaves , Hydroxy Acids , Triterpenes/pharmacology
11.
Eur J Pediatr ; 2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38684534

ABSTRACT

While neonatal necrotising enterocolitis (NEC) is associated with high mortality rates in newborns, survivors can face long-term sequelae. However, the relationship between NEC and neurodevelopmental impairment (NDI) in preterm infants remains unclear. To explore the relationship between neonatal NEC and neurodevelopmental outcomes in preterm infants, we searched PubMed, EMBASE, and the Cochrane Library from their inception to February 2024 for relevant studies. Studies included were cohort or case-control studies reporting neurodevelopmental outcomes of NEC in preterm infants. Two independent investigators extracted data regarding brain damage and neurodevelopmental outcomes in these infants at a corrected age exceeding 12 months. Odds ratios (ORs) were pooled using a random effects model. We included 15 cohort studies and 18 case-control studies, encompassing 60,346 infants. Meta-analysis of unadjusted and adjusted ORs demonstrated a significant association between NEC and increased odds of NDI (OR 2.15, 95% CI 1.9-2.44; aOR 1.89, 95% CI 1.46-2.46). Regarding brain injury, pooled crude ORs indicated an association of NEC with severe intraventricular haemorrhage (IVH) (OR 1.42, 95% CI 1.06-1.92) and periventricular leucomalacia (PVL) (OR 2.55, 95% CI 1.76-3.69). When compared with conservatively treated NEC, surgical NEC potentially carries a higher risk of NDI (OR 1.78, 95% CI 1.09-2.93) and severe IVH (OR 1.57, 95% CI 1.20-2.06). However, the risk of PVL did not show a significant difference (OR 1.60, 95% CI 0.47-5.40). CONCLUSIONS:  Our meta-analysis provides evidence suggesting an association between NEC and NDI. Additionally, the severity of intestinal lesions appears to correlate with a higher risk of NDI. Further high-quality studies with comprehensive adjustments for potential confounding factors are required to definitively establish whether the association with NDI is causal. WHAT IS KNOWN: • NEC is a serious intestinal disease in the neonatal period with a high mortality rate, and surviving children may have digestive system sequelae. • Compared with non-NEC preterm infants, the reported incidences of brain injury and neurodevelopmental disorders in NEC preterm infants are not the same. WHAT IS NEW: • The risk of neonatal brain injury and neurodevelopmental disorders in preterm infants with NEC is higher than that in non-NEC infants, and the risk of NDI in surgical NEC infants is higher than that in the conservative treatment group. • NEC may increase the risk of motor, cognitive, language development delays, and attention deficits in children.

12.
J Proteome Res ; 23(5): 1559-1570, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38603467

ABSTRACT

The ongoing evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to the emergence of different variants of concerns with immune evasion that have been prevalent over the past three years. Nanobodies, the functional variable regions of camelid heavy-chain-only antibodies, have garnered interest in developing neutralizing antibodies due to their smaller size, structural stability, ease of production, high affinity, and low immunogenicity, among other characteristics. In this work, we describe an integrated proteomics platform for the high-throughput screening of nanobodies against different SARS-CoV-2 spike variants. To demonstrate this platform, we immunized a camel with subunit 1 (S1) of the wild-type spike protein and constructed a nanobody phage library. The binding and neutralizing activities of the nanobodies against 72 spike variants were then measured, resulting in the identification of two nanobodies (C-282 and C-39) with broad neutralizing activity against six non-Omicron variants (D614G, Alpha, Beta, Gamma, Delta, Kappa) and five Omicron variants (BA.1-5). Their neutralizing capability was validated using in vitro pseudovirus-based neutralization assays. All these results demonstrate the utility of our proteomics platform to identify new nanobodies with broad neutralizing capability and to develop a treatment for patients with SARS-CoV-2 variant infection in the future.


Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , COVID-19 , Camelus , Proteomics , SARS-CoV-2 , Single-Domain Antibodies , Spike Glycoprotein, Coronavirus , SARS-CoV-2/immunology , Antibodies, Neutralizing/immunology , Single-Domain Antibodies/immunology , Single-Domain Antibodies/chemistry , Proteomics/methods , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Animals , Humans , COVID-19/immunology , COVID-19/virology , Antibodies, Viral/immunology , Neutralization Tests
13.
Nat Struct Mol Biol ; 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38600323

ABSTRACT

Many large molecular machines are too elaborate to assemble spontaneously and are built through ordered pathways orchestrated by dedicated chaperones. During assembly of the core particle (CP) of the proteasome, where protein degradation occurs, its six active sites are simultaneously activated via cleavage of N-terminal propeptides. Such activation is autocatalytic and coupled to fusion of two half-CP intermediates, which protects cells by preventing activation until enclosure of the active sites within the CP interior. Here we uncover key mechanistic aspects of autocatalytic activation, which proceeds through alignment of the ß5 and ß2 catalytic triad residues, respectively, with these triads being misaligned before fusion. This mechanism contrasts with most other zymogens, in which catalytic centers are preformed. Our data also clarify the mechanism by which individual subunits can be added in a precise, temporally ordered manner. This work informs two decades-old mysteries in the proteasome field, with broader implications for protease biology and multisubunit complex assembly.

14.
Virulence ; 15(1): 2339703, 2024 12.
Article in English | MEDLINE | ID: mdl-38576396

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has posed enormous challenges to global public health. The use of antibiotics has greatly increased during the SARS-CoV-2 epidemic owing to the presence of bacterial co-infection and secondary bacterial infections. The antibiotics daptomycin (DAP) is widely used in the treatment of infectious diseases caused by gram-positive bacteria owing to its highly efficient antibacterial activity. It is pivotal to study the antibiotics usage options for patients of coronavirus infectious disease (COVID-19) with pneumonia those need admission to receive antibiotics treatment for bacterial co-infection in managing COVID-19 disease. Herein, we have revealed the interactions of DAP with the S protein of SARS-CoV-2 and the variant Omicron (B1.1.529) using the molecular docking approach and Omicron (B1.1.529) pseudovirus (PsV) mimic invasion. Molecular docking analysis shows that DAP has a certain degree of binding ability to the S protein of SARS-CoV-2 and several derived virus variants, and co-incubation of 1-100 µM DAP with cells promotes the entry of the PsV into human angiotensin-converting enzyme 2 (hACE2)-expressing HEK-293T cells (HEK-293T-hACE2), and this effect is related to the concentration of extracellular calcium ions (Ca2+). The PsV invasion rate in the HEK-293T-hACE2 cells concurrently with DAP incubation was 1.7 times of PsV infection alone. In general, our findings demonstrate that DAP promotes the infection of PsV into cells, which provides certain reference of antibiotics selection and usage optimization for clinicians to treat bacterial coinfection or secondary infection during SARS-CoV-2 infection.


Subject(s)
COVID-19 , Daptomycin , Molecular Docking Simulation , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , SARS-CoV-2/drug effects , Humans , Spike Glycoprotein, Coronavirus/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Daptomycin/pharmacology , Daptomycin/therapeutic use , COVID-19/virology , Anti-Bacterial Agents/pharmacology , Protein Binding , Virus Internalization/drug effects , Betacoronavirus/drug effects , Pandemics , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , HEK293 Cells , Angiotensin-Converting Enzyme 2/metabolism , Angiotensin-Converting Enzyme 2/chemistry
15.
BMC Bioinformatics ; 25(1): 158, 2024 Apr 20.
Article in English | MEDLINE | ID: mdl-38643066

ABSTRACT

BACKGROUND: Motif finding in Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) data is essential to reveal the intricacies of transcription factor binding sites (TFBSs) and their pivotal roles in gene regulation. Deep learning technologies including convolutional neural networks (CNNs) and graph neural networks (GNNs), have achieved success in finding ATAC-seq motifs. However, CNN-based methods are limited by the fixed width of the convolutional kernel, which makes it difficult to find multiple transcription factor binding sites with different lengths. GNN-based methods has the limitation of using the edge weight information directly, makes it difficult to aggregate the neighboring nodes' information more efficiently when representing node embedding. RESULTS: To address this challenge, we developed a novel graph attention network framework named MMGAT, which employs an attention mechanism to adjust the attention coefficients among different nodes. And then MMGAT finds multiple ATAC-seq motifs based on the attention coefficients of sequence nodes and k-mer nodes as well as the coexisting probability of k-mers. Our approach achieved better performance on the human ATAC-seq datasets compared to existing tools, as evidenced the highest scores on the precision, recall, F1_score, ACC, AUC, and PRC metrics, as well as finding 389 higher quality motifs. To validate the performance of MMGAT in predicting TFBSs and finding motifs on more datasets, we enlarged the number of the human ATAC-seq datasets to 180 and newly integrated 80 mouse ATAC-seq datasets for multi-species experimental validation. Specifically on the mouse ATAC-seq dataset, MMGAT also achieved the highest scores on six metrics and found 356 higher-quality motifs. To facilitate researchers in utilizing MMGAT, we have also developed a user-friendly web server named MMGAT-S that hosts the MMGAT method and ATAC-seq motif finding results. CONCLUSIONS: The advanced methodology MMGAT provides a robust tool for finding ATAC-seq motifs, and the comprehensive server MMGAT-S makes a significant contribution to genomics research. The open-source code of MMGAT can be found at https://github.com/xiaotianr/MMGAT , and MMGAT-S is freely available at https://www.mmgraphws.com/MMGAT-S/ .


Subject(s)
Chromatin Immunoprecipitation Sequencing , Genomics , Humans , Animals , Mice , Binding Sites , Protein Binding , Genomics/methods , Chromatin/genetics , Transcription Factors/metabolism
16.
PeerJ Comput Sci ; 10: e1944, 2024.
Article in English | MEDLINE | ID: mdl-38660147

ABSTRACT

Electrical impedance tomography (EIT) provides an indirect measure of the physiological state and growth of the maize ear by reconstructing the distribution of electrical impedance. However, the two-dimensional (2D) EIT within the electrode plane finds it challenging to comprehensively represent the spatial distribution of conductivity of the intact maize ear, including the husk, kernels, and cob. Therefore, an effective method for 3D conductivity reconstruction is necessary. In practical applications, fluctuations in the contact impedance of the maize ear occur, particularly with the increase in the number of grids and computational workload during the reconstruction of 3D spatial conductivity. These fluctuations may accentuate the ill-conditioning and nonlinearity of the EIT. To address these challenges, we introduce RFNetEIT, a novel computational framework specifically tailored for the absolute imaging of the three-dimensional electrical impedance of maize ear. This strategy transforms the reconstruction of 3D electrical conductivity into a regression process. Initially, a feature map is extracted from measured boundary voltage via a data reconstruction module, thereby enhancing the correlation among different dimensions. Subsequently, a nonlinear mapping model of the 3D spatial distribution of the boundary voltage and conductivity is established, utilizing the residual network. The performance of the proposed framework is assessed through numerical simulation experiments, acrylic model experiments, and maize ear experiments. Our experimental results indicate that our method yields superior reconstruction performance in terms of root-mean-square error (RMSE), correlation coefficient (CC), structural similarity index (SSIM), and inverse problem-solving time (IPST). Furthermore, the reconstruction experiments on maize ears demonstrate that the method can effectively reconstruct the 3D conductivity distribution.

17.
Quant Imaging Med Surg ; 14(3): 2539-2555, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38545066

ABSTRACT

Background: Disease diagnosis in chest X-ray images has predominantly relied on convolutional neural networks (CNNs). However, Vision Transformer (ViT) offers several advantages over CNNs, as it excels at capturing long-term dependencies, exploring correlations, and extracting features with richer semantic information. Methods: We adapted ViT for chest X-ray image analysis by making the following three key improvements: (I) employing a sliding window approach in the image sequence feature extraction module to divide the input image into blocks to identify small and difficult-to-detect lesion areas; (II) introducing an attention region selection module in the encoder layer of the ViT model to enhance the model's ability to focus on relevant regions; and (III) constructing a parallel patient metadata feature extraction network on top of the image feature extraction network to integrate multi-modal input data, enabling the model to synergistically learn and expand image-semantic information. Results: The experimental results showed the effectiveness of our proposed model, which had an average area under the curve value of 0.831 in diagnosing 14 common chest diseases. The metadata feature network module effectively integrated patient metadata, further enhancing the model's accuracy in diagnosis. Our ViT-based model had a sensitivity of 0.863, a specificity of 0.821, and an accuracy of 0.834 in diagnosing these common chest diseases. Conclusions: Our model has good general applicability and shows promise in chest X-ray image analysis, effectively integrating patient metadata and enhancing diagnostic capabilities.

18.
Bioinformatics ; 40(4)2024 Mar 29.
Article in English | MEDLINE | ID: mdl-38426310

ABSTRACT

MOTIVATION: Predicting molecular properties is a pivotal task in various scientific domains, including drug discovery, material science, and computational chemistry. This problem is often hindered by the lack of annotated data and imbalanced class distributions, which pose significant challenges in developing accurate and robust predictive models. RESULTS: This study tackles these issues by employing pretrained molecular models within a few-shot learning framework. A novel dynamic contrastive loss function is utilized to further improve model performance in the situation of class imbalance. The proposed MolFeSCue framework not only facilitates rapid generalization from minimal samples, but also employs a contrastive loss function to extract meaningful molecular representations from imbalanced datasets. Extensive evaluations and comparisons of MolFeSCue and state-of-the-art algorithms have been conducted on multiple benchmark datasets, and the experimental data demonstrate our algorithm's effectiveness in molecular representations and its broad applicability across various pretrained models. Our findings underscore MolFeSCues potential to accelerate advancements in drug discovery. AVAILABILITY AND IMPLEMENTATION: We have made all the source code utilized in this study publicly accessible via GitHub at http://www.healthinformaticslab.org/supp/ or https://github.com/zhangruochi/MolFeSCue. The code (MolFeSCue-v1-00) is also available as the supplementary file of this paper.


Subject(s)
Algorithms , Benchmarking , Drug Discovery , Models, Molecular , Software
19.
J Org Chem ; 89(7): 4619-4627, 2024 Apr 05.
Article in English | MEDLINE | ID: mdl-38536672

ABSTRACT

Allyl sulfones are commonly present in bioactive compounds and organic building blocks. This work introduces a photocatalytic radical addition-elimination reaction involving readily accessible sulfonyl chlorides and allyl bromides. It delivers structurally diverse allylic sulfones in moderate to excellent yields, showcasing a high tolerance to functional groups. Notably, this method operates under mild reaction conditions without the need for oxidants, stoichiometric reducing metals, or additives.

20.
Anal Biochem ; 689: 115495, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38431142

ABSTRACT

RNA modification, N4-acetylcytidine (ac4C), is enzymatically catalyzed by N-acetyltransferase 10 (NAT10) and plays an essential role across tRNA, rRNA, and mRNA. It influences various cellular functions, including mRNA stability and rRNA biosynthesis. Wet-lab detection of ac4C modification sites is highly resource-intensive and costly. Therefore, various machine learning and deep learning techniques have been employed for computational detection of ac4C modification sites. The known ac4C modification sites are limited for training an accurate and stable prediction model. This study introduces GANSamples-ac4C, a novel framework that synergizes transfer learning and generative adversarial network (GAN) to generate synthetic RNA sequences to train a better ac4C modification site prediction model. Comparative analysis reveals that GANSamples-ac4C outperforms existing state-of-the-art methods in identifying ac4C sites. Moreover, our result underscores the potential of synthetic data in mitigating the issue of data scarcity for biological sequence prediction tasks. Another major advantage of GANSamples-ac4C is its interpretable decision logic. Multi-faceted interpretability analyses detect key regions in the ac4C sequences influencing the discriminating decision between positive and negative samples, a pronounced enrichment of G in this region, and ac4C-associated motifs. These findings may offer novel insights for ac4C research. The GANSamples-ac4C framework and its source code are publicly accessible at http://www.healthinformaticslab.org/supp/.


Subject(s)
Cytidine/analogs & derivatives , Machine Learning , RNA , RNA Stability
SELECTION OF CITATIONS
SEARCH DETAIL
...