Biology subjects

Liu, X.

Publications and source records attributed to Liu, X..

At least 829 records · Page 46Linked to original sources

bioRxiv2024

SlWRKY80 recruits SlHDA1 to regulates the tomato fruit ripening and color transformation

Fruit ripening involves key transcription factors (TF). Despite the established importance of WRKY TFs in plant development, the involvement of WRKY and its underlying mechanism in the regulation of fruit ripening and color transformation remain unclear. Here, we discovered a phenomenon where SlWRKY80 is involved in the ripening and color transformation of tomato. Overexpression of SlWRKY80 shortened the color transition cycle of tomato fruit, whereas loss-of-function mutation in SlWRKY80 delays this process. On the 7th day after the color breakdown (Break+7), the fruit color was bright red in SlWRKY80-overexpression lines. SlWRKY80 could bind to downstream promoters of SlSGR1 and SlPSY1, thereby exerting a positive regulatory effect on the expression levels of SlSGR1 and SlPSY1. This regulatory activity led to the facilitation of chlorophyll a decomposition and carotenoid synthesis during the transition of fruit color, ultimately accelerating fruit ripening and color change. The SlWRKY80 knockout lines (slwrky80cr-3 and slwrky80cr-4) showed light red. Thr (The 69th amino acid) mutated to Ser of SlWRKY80 (slwrky80cr-46), SlHDA1 was recruited as a regulatory factor to enhance the regulation of downstream SlPSY1 by SlWRKY80, and inhibited the SlSGR1 expression by SlWRKY80 which maybe the reason why the slwrky80cr-46 knockout lines exhibited brown color. In conclusion, SlWRKY80 regulates the expression of SlSGR1 and SlPSY1 by recruiting SlHDA1, thereby regulating chlorophyll decomposition and carotenoid synthesis, and further participating in fruit maturation and related fruit color formation. This research has important guiding significance for breeding tomato germplasm with excellent commercial traits.

plant biology↗

bioRxiv2024

Ketone body 3-hydroxybutyrate alleviates CCl4-induced liver fibrosis in mice through anti-inflammatory effects

3-Hydroxybutyrate (3HB) is an important metabolite and regulatory molecule produced in liver. Previous studies have shown that 3HB could be beneficial to many diseases, including brain diseases, diabetes, and most importantly, inflammation and liver related injury. Therefore, the effect of 3HB on liver fibrosis, one key step of liver diseases which proved to be reversible, is urgent to explore. In this study, the CCl4-induced mouse model of liver fibrosis has been successfully constructed and treated by 3HB. The results demonstrate that 3HB could alleviate CCl4-induced liver injury and inflammation in mice, decrease the accumulation of collagen, the expression of pro-fibrotic genes as well as inflammatory factors, and finally the degree of liver fibrosis. The transcriptome data recovers that the anti-fibrotic effect of 3HB might be exerted through several ways, such as regulating mitochondrial function, reducing oxidative stress and p53 signaling pathways, proposing a safe and relatively fast possibility for the treatment of liver fibrosis.

biochemistry↗

bioRxiv2024

Dual-targeted nanoparticulate drug delivery systems for enhancing triple-negative breast cancer treatment

The efficacy of DNA-damaging agents, such as the topoisomerase I inhibitor SN38, is often compromised by the robust DNA repair mechanisms in tumor cells, notably homologous recombination (HR) repair. Addressing this challenge, we introduce a novel nano-strategy utilizing binary tumor-killing mechanisms to enhance the therapeutic impact of DNA damage and mitochondrial dysfunction in cancer treatment. Our approach employs a synergistic drug pair comprising SN38 and the BET inhibitor JQ-1. We synthesized two prodrugs by conjugating linoleic acid (LA) to SN38 and JQ-1 via a cinnamaldehyde thioacetal (CT) bond, facilitating co-delivery. These prodrugs co-assemble into a nanostructure, referred to as SJNP, in an optimal synergistic ratio. SJNP was validated for its efficacy at both the cellular and tissue levels, where it primarily disrupts the transcription factor protein BRD4. This disruption leads to downregulation of BRCA1 and RAD51, impairing the HR process and exacerbating DNA damage. Additionally, SJNP releases cinnamaldehyde (CA) upon CT linkage cleavage, elevating intracellular ROS levels in a self-amplifying manner and inducing ROS-mediated mitochondrial dysfunction. Our results indicate that SJNP effectively targets murine triple-negative breast cancer (TNBC) with minimal adverse toxicity, showcasing its potential as a formidable opponent in the fight against cancer.

cancer biology↗

bioRxiv2024

The alpha4 nicotinic acetylcholine receptor is necessary for the initiation of organophosphate-induced neuronal hyperexcitability

Acute intoxication with organophosphorus (OP) cholinesterase inhibitors can produce seizures that rapidly progress to life-threatening status epilepticus. Significant research effort has been invested investigating the involvement of muscarinic acetylcholine receptors (mAChRs) in OP-induced seizure activity. In contrast, there has been far less effort focused on nicotinic AChRs (nAChRs) in this context. Here, we address this data gap using a combination of in vitro and in vivo models. Pharmacological antagonism and genetic deletion of 4, but not 7, nAChR subunits prevented or significantly attenuated OP-induced electrical spike activity in acute hippocampal slices and seizure activity in mice, indicating that 4 nAChR activation is necessary for neuronal hyperexcitability triggered by acute OP exposures. These findings not only suggest that therapeutic strategies for inhibiting the 4 nAChR subunit warrant further investigation as prophylactic and acute treatments for acute OP-induced seizures, but also provide mechanistic insight into the role of the nicotinic cholinergic system in seizure generation.

pharmacology and toxicology↗

bioRxiv2024

Predicting the Assembly Order of Protein Complexes by Multi-Temperature Coarse-Grained Simulations

Assembly of a protein complex is very important to its biological function, which can be investigated by determining assembly/disassembly order of its protein subunits. Although static structures of many protein complexes are available in the protein data bank, their assembly/disassembly orders of subunits are largely unknown. In addition to experimental techniques for studying subcomplexes in the assembly/disassembly of a protein complex, computational methods can be used to predict the assembly/disassembly order. Since sampling is a nontrivial issue in simulating the assembly/disassembly process, coarse-grained simulations are more efficient than atomic simulations are. In this work, we developed computational protocols for predicting assembly/disassembly orders of protein complexes using coarse-grained simulations. The protocols were illustrated using two protein complexes, and the predicted assembly/disassembly orders are consistent with available experimental data.

biophysics↗

bioRxiv2024

LRG1 promotes atherosclerosis by activating macrophages

BackgroundAtherosclerosis is a chronic inflammatory disease of the arterial wall characterized by the accumulation of cholesterol-rich lipoproteins in macrophages. Leucine-rich alpha-2 glycoprotein 1 (LRG1) is a circulating protein associated with inflammation, however, its role in atherosclerosis remains unclear. This study identified its role in macrophage pro-inflammatory differentiation and revealed the relationship between LRG1 and atherosclerosis. MethodWe evaluated the impact of LRG1 on atherosclerosis progression by analyzing atherosclerotic tissue and serum samples from patients with coronary artery disease (CAD) and healthy individuals and analyzed its role in such a process using two types of mice models: Apoe knock-out mice (Apoe-/-) and Apoe and Lrg1 double knock-out mice (Apoe-/-/Lrg1-/-). These mice were fed with a high-fat diet for 16 to 32 weeks to simulate conditions exacerbating atherosclerosis. To examine the effects of inhibiting LRG1 on atherogenesis, we administered intraperitoneal injections of LRG1 neutralizing antibody (50g/kg) weekly to Apoe-/- mice for 8 weeks. We conducted in vitro assays using bone marrow-derived macrophages isolated from wild-type mice and analyzed transcriptional signatures using RNA sequencing. Additionally, we utilized small molecular inhibitors to validate the signaling pathway through which LRG1 promotes macrophage-driven inflammation. ResultsLRG1 levels were found to be elevated in patients with atherosclerosis and correlated with higher levels of a plasma pro-inflammatory biomarker high-sensitive C-reactive protein (hsCRP), and several macrophage-related pro-inflammatory markers including CD68, VE-Cadherin and VCAM-1. In a high fat diet induced Apoe-/- mouse atherosclerosis model, the deletion of LRG1 gene significantly delayed atherogenesis progression and reduced levels of macrophage-related pro-inflammatory cytokines. Addition of purified LRG1 to cultured macrophages stimulated those macrophages to pro-inflammatory M1-like polarization regulated by the activation of ERK and JNK pathways. An anti-LRG1 neutralizing antibody effectively blocked LRG1-induced macrophage M1-like polarization in vitro and conferred therapeutic benefits to animals with ApoE deficiency-induced atherosclerosis. ConclusionLRG1 plays an important pro-inflammatory role in atherosclerosis by influencing macrophage polarization towards a pro-inflammatory state. The inhibition of LRG1 with neutralizing antibodies may offer a potential therapeutic strategy for patients with atherosclerosis by mitigating the pro-inflammatory response and delaying disease progression, offering a novel therapy in atherosclerosis management. Translational PerspectiveAtherosclerosis, a persistent inflammatory condition affecting the arterial wall, serves as the underlying pathophysiological basis for acute ischemic cardiovascular events. The involvement of macrophages is crucial in the advancement of atherosclerosis. In this investigation, heightened levels of plasma LRG1 were observed in individuals with coronary artery disease. Moreover, this study presents initial evidence highlighting LRG1 as a pivotal activator of macrophages, instigating a pro-inflammatory M1 polarization during atherogenesis through the activation of ERK1/2 and JNK pathways. The use of an anti-LRG1 neutralizing antibody demonstrated a delay in atherosclerosis progression in an animal model, suggesting a potential therapeutic target for atherosclerosis treatment. Suppression of LRG1 production could impede atherosclerosis advancement and enhance plaque stability. Utilizing neutralizing antibodies against LRG1 emerges as a promising therapeutic approach for treating atherosclerosis.

pathology↗

bioRxiv2024

Self-inspired learning to denoise for live-cell super-resolution microscopy

Every collected photon is precious in live-cell super-resolution (SR) fluorescence microscopy for contributing to breaking the diffraction limit with the preservation of temporal resolvability. Here, to maximize the utilization of accumulated photons, we propose SN2N, a Self-inspired Noise2Noise engine with self-supervised data generation and self-constrained learning process, which is an effective and data-efficient learning-based denoising solution for high-quality SR imaging in general. Through simulations and experiments, we show that the SN2Ns performance is fully competitive to the supervised learning methods but circumventing the need for large training-set and clean ground-truth, in which a single noisy frame is feasible for training. By one-to-two orders of magnitude increased photon efficiency, the direct applications on various confocal-based SR systems highlight the versatility of SN2N for allowing fast and gentle 5D SR imaging. We also integrated SN2N into the prevailing SR reconstructions for artifacts removal, enabling efficient reconstructions from limited photons. Together, we anticipate our SN2N and its integrations could inspire further advances in the rapidly developing field of fluorescence imaging and benefit subsequent precise structure segmentation irrespective of noise conditions.

bioengineering↗

bioRxiv2024

Noncaloric monosaccharides induce excessive sprouting angiogenesis in zebrafish via foxo1a-marcksl1a signal

Artificially sweetened beverages containing noncaloric monosaccharides were suggested as healthier alternatives to sugar-sweetened beverages. Nevertheless, the potential detrimental effects of these noncaloric monosaccharides on blood vessel function remain inadequately understood. We have established a zebrafish model that exhibits significant excessive angiogenesis induced by high glucose, resembling the hyperangiogenic characteristics observed in proliferative diabetic retinopathy (PDR). Utilizing this model, we observed that glucose and noncaloric monosaccharides could induce excessive formation of blood vessels, especially intersegmental vessels (ISVs). The excessively branched vessels were observed to be formed by ectopic activation of quiescent endothelial cells (ECs) into tip cells. Single-cell transcriptomic sequencing analysis of the endothelial cells in the embryos exposed to high glucose revealed an augmented ratio of capillary ECs, proliferating ECs, and a series of upregulated proangiogenic genes. Further analysis and experiments validated that reduced foxo1a mediated the excessive angiogenesis induced by monosaccharides via up-regulating the expression of marcksl1a. This study has provided new evidence showing the negative effects of noncaloric monosaccharides on the vascular system and the underlying mechanisms.

pharmacology and toxicology↗

bioRxiv2024

miR-100 and miR-125b Contribute to Enhanced Growth and Invasiveness

Extracellular communication via the transfer of vesicles and nanoparticles is now recognized to play an important role in tumor microenvironment interactions. Cancer cells upregulate and secrete abundant levels of miR-100 and miR-125b that can alter gene expression by both cell- and non-cell-autonomous mechanisms. We previously showed that these miRNAs activate Wnt signaling in colorectal cancer (CRC) through noncanonical pairing with 5 negative regulators of Wnt signaling. To identify additional targets of miR-100 and miR-125b, we used bioinformatic approaches comparing multiple CRC cell lines, including knockout lines lacking one or both of these miRNAs. From an initial list of 96 potential mRNA targets, we tested 15 targets with 8 showing significant downregulation in the presence of miR-100 and miR-125b. Among these, Cingulin (CGN) and Protein tyrosine phosphatase receptor type-R (PTPRR) are downregulated in multiple cancers, consistent with regulation by increased levels of miR-100 and miR-125b. We also show that increased cellular levels of miR-100 and miR-125b enhance 3D growth and invasiveness in CRC and glioblastoma cell lines. Lastly, we demonstrate that extracellular transfer of miR-100 and miR-125b can silence both reporter and endogenous mRNA targets in recipient cells and also increase the invasiveness of recipient spheroid colonies when grown under 3D conditions in type I collagen.

cancer biology↗

bioRxiv2024

5-Fluorouracil Treatment Represses Pseudouridine-Containing Small RNA Export into Extracellular Vesicles

5-fluorouracil (5-FU) has been used for chemotherapy for colorectal and other cancers for over 50 years. The prevailing view of its mechanism of action is inhibition of thymidine synthase leading to defects in DNA replication and repair. However, 5-FU is also incorporated into RNA causing toxicity due to defects in RNA metabolism, inhibition of pseudouridine modification, and altered ribosome function. Here, we examine the impact of 5-FU on the expression and export of small RNAs (sRNAs) into small extracellular vesicles (sEVs). Moreover, we assess the role of 5-FU in regulation of post-transcriptional sRNA modifications (PTxM) using mass spectrometry approaches. EVs are secreted by all cells and contain a variety of proteins and RNAs that can function in cell-cell communication. PTxMs on cellular and extracellular sRNAs provide yet another layer of gene regulation. We found that treatment of the colorectal cancer (CRC) cell line DLD-1 with 5-FU led to surprising differential export of miRNA snRNA, and snoRNA transcripts. Strikingly, 5-FU treatment significantly decreased the levels of pseudouridine on both cellular and secreted EV sRNAs. In contrast, 5-FU exposure led to increased levels of cellular sRNAs containing a variety of methyl-modified bases. Our results suggest that 5-FU exposure leads to altered expression, base modifications, and mislocalization of EV base-modified sRNAs.

molecular biology↗

bioRxiv2024

Cerebral Blood Volume Modulates Glymphatic Influx Through Extra-ventricular Cerebrospinal Fluid Volume

The glymphatic system facilitates waste removal via cerebrospinal fluid (CSF) influx alongside perivascular spaces throughout the brain. Vasomotion, the slow motion of blood vessel (0.1-0.3 Hz), has been found to be one of the driving forces for perivascular clearance, but it is not clear whether more chronical change of vessel diameter, as reflected by macroscopic cerebral blood volume (CBV), has any impact on glymphatic function. Combining multimodal mouse MRI techniques, we investigated the relationship among glymphatic influx, CBV, CSF volume and EEG power under six different conditions (awake, dexmedetomidine, isoflurane, isoflurane/dexmedetomidine, ketamine/xylazine and awake with caffeine). We found dexmedetomidine and caffeine enhanced glymphatic influx, while isoflurane reduced it compared with awake condition. Quantitative CBV imaging revealed that glymphatic influx was negatively correlated to CBV across the above conditions. Furthermore, such negative correlation was found to be mediated in part by changes of extra-ventricular CSF volume, which was quantified using T1 MRI. Taken together, our results suggest that CBV is a consciousness independent modulator of glymphatic function and modulates glymphatic influx through extra-ventricular CSF volume. This new finding opens potential avenues to enhance brain waste clearance by regulating CBV, which could be beneficial for protein deposition related neurological diseases. TeaserCBV is a consciousness independent modulator of glymphatic function and modulates glymphatic influx through extra-ventricular CSF volume.

neuroscience↗

bioRxiv2024

Inhibition of Alpha Interferon-Induced miR-873 Negatively Affects the Hepatitis B Virus Expression

BackgroundAlpha interferon (IFN-)-based therapy can effectively treat chronic hepatitis B virus (HBV) infection, which remains a serious public health problem. This study aims to identify the potential biomarker of IFN treatment and investigate the effects of miR-873 on chronic hepatitis B (CHB). MethodsWe utilized the random forest to screen core differentially expressed miRNAs (DEmiRNAs) based on the miRNA (GSE29911) dataset. DEmiRNAs expressions were determined in clinical samples from CHB patients and normal controls. HBV-transfected hepatoma cell lines were constructed for vitro study. Quantitative real-time reverse transcription PCR (RT-qPCR) was used to determine miRNA mRNA expressions. ELISA assays were used to detect the secretion levels of HBsAg and HBeAg. ResultsBoruta feature selection revealed miR-873 hinting at a predictive marker for IFN response. MiR-873 was significantly up-regulated in the CHB patients, as compared with normal controls (P<0.001). Increased expression of miR-873 was also found in HBV-infected cells (P<0.001). With IFN- treatment, miR-873 was significantly down-regulated in HBV-infected Huh-7 and HepG-NTCP cells (P<0.05). IFN- treatment and miR-873 inhibitor significantly reduced HBsAg and HBeAg level (P<0.05). The inhibitory effect was enhanced by blocking the IFN--induced miR-873 downregulation by inhibitor transfection (P<0.05). In miR-873 mimic-treated cells, the inhibitory effect was greatly supressed by blocking the IFN--induced miR-873 downregulation by mimic transfection (P< 0.01). ConclusionWe provide evidence that inhibition of miR-873 by IFN- enhances the antiviral effects of IFN-. Our study provides a potential strategy to enhance the anti-HBV effect of IFN- by inhibiting miR-873 expression.

molecular biology↗

bioRxiv2024

Blocker-SELEX: A Structure-guided Strategy for Developing Inhibitory Aptamers Disrupting Undruggable Transcription Factor Interactions

Despite the well-established significance of transcription factors (TFs) in pathogenesis, their utilization as pharmacological targets has been limited by the inherent challenges associated with modulating their protein-protein and protein-DNA interactions. The lack of defined small-molecule binding pockets and the nuclear localization of TFs do not favor the use of small-molecule inhibitors, or neutral antibodies, in blocking TF interactions. Aptamers are short oligonucleotides exhibiting high affinity and specificity for a diverse range of targets. Large molecular weights, expansive blocking surfaces and efficient cellular internalization make aptamers a compelling molecular tool for use as traditional TF interaction modulators. Here, we report a structure-guided design strategy called Blocker-SELEX to develop inhibitory aptamers (iAptamer) that selectively block TF interactions. Our approach led to the discovery of iAptamers that cooperatively disrupts SCAF4/SCAF8-RNA Polymerase II (RNAP2) interactions, thereby dysregulating RNAP2-dependent gene expression and splicing and, in turn, leading to the impairment of cell proliferation. This approach was further applied to develop iAptamers to efficiently block WDR5-MYC interaction with a nexus in cancer. Taken together, our study highlights the potential of Blocker-SELEX in developing iAptamers that effectively disrupt potentially pathogenic TF interactions with attendant implications for iAptamers as chemical tools for use in the study of biological functions of TF interactions, but also for potential use in nucleic acids drug discovery.

biochemistry↗

bioRxiv2024

Multiplex Imaging Reveals Novel Subcellular, Microenvironmental, and Racial Patterns of MRTFA/B Activation in Invasive Breast Cancers and Metastases

Breast cancer progression and metastasis involve the action of multiple transcription factors in tumors and in the cells of the tumor microenvironment (TME) and understanding how these transcription factors are coordinated can guide novel therapeutic strategies. Myocardin related transcription factors A and B (MRTFA/B) are two related transcription factors that redundantly control cancer cell invasion and metastasis in mouse models of breast cancer, but their roles in human cancer are incompletely understood. Here, we used a combination of multiplexed immunofluorescence and bioinformatics analyses to show that MRTFA/B are concurrently activated in tumor cells, but they show distinct patterns of expression across different histological subtypes and in the TME. Importantly, MRTFA expression was elevated in metastatic tumors of African American patients, who disproportionately die from breast cancer. Interestingly, in contrast to publicly available mRNA expression data, MRTFA was similarly expressed across estrogen receptor (ER) positive and negative breast tumors, while MRTFB expression was highest in ER+ breast tumors. Furthermore, MRTFA was specifically expressed in the perivascular antigen presenting cells (APCs) and its expression correlated with the expression of the immune checkpoint protein V-set immunoregulatory receptor (VSIR). These results provide unique insights into how MRTFA and MRTFB can promote metastasis in human cancer, into the racial disparities of their expression patterns, and their function within the complex breast cancer TME. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/573909v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@12037b3org.highwire.dtl.DTLVardef@28e2feorg.highwire.dtl.DTLVardef@4e95e1org.highwire.dtl.DTLVardef@152019b_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2024

Cytochrome P450 Enzyme Design by Constraining Catalytic Pocket in Diffusion model

Although cytochrome P450 enzymes are the most versatile biocatalysts in nature, there is insufficient comprehension of the molecular mechanism underlying their functional innovation process. Here, by combining ancestral sequence reconstruction, reverse mutation assay and structure analysis, we identified five founder residues in the catalytic pocket of flavone 6-hydroxylase (F6H) and proposed a "three-point fixation" model to elucidate the functional innovation mechanisms of P450s in nature. According to this design principle of catalytic pocket, we further developed a de novo diffusion model (P450Diffusion) to generate artificial P450s. Ultimately, among the 17 non-natural P450s we generated, ten designs exhibited significant F6H activity and six exhibited a 1.3- to 3.5-fold increase in catalytic capacity compared to the natural CYP706X1. This work not only explores the design principle of catalytic pockets of P450s, but also provides an insight into the artificial design of P450 enzymes with desired functions.

molecular biology↗

bioRxiv2024

AXOLOTL: an accurate method for detecting aberrant gene expression in rare diseases using coexpression constraints

BackgroundThe assessment of aberrant transcription events in patients with rare diseases holds promise for significantly enhancing the prioritization of causative genes, a practice already widely employed in clinical settings to increase diagnostic accuracy. Nevertheless, the entangled correlation between genes presents a substantial challenge for accurate identification of causal genes in clinical diagnostic scenarios. Currently, none of the existing methods are capable of effectively modeling gene correlation. MethodsWe propose a novel unsupervised method, AXOLOTL, to identify aberrant gene expression events in an RNA expression matrix. AXOLOTL effectively addresses biological confounders by incorporating coexpression constraints. ResultsWe demonstrated the superior performance of AXOLOTL on representative RNA-seq datasets, including those from the GTEx healthy cohort, mitochondrial disease cohort and Collagen VI-related dystrophy cohort. Furthermore, we applied AXOLOTL to real case studies and demonstrated its ability to accurately identify aberrant gene expression and facilitate the prioritization of pathogenic variants.

bioinformatics↗

bioRxiv2024

A Neural Network for High-Precise and Well-Interpretable Electrocardiogram Classification

Manual heart disease diagnosis with the electrocardiogram (ECG) is intractable due to the intertwined signal features and lengthy diagnosis procedure, especially for the 24-hour dynamic ECG signals. Consequently, even experienced cardiologists may face difficulty in producing all accurate ECG reports. In recent years, neural network-based automatic ECG diagnosis methods have exhibited promising performance, suggesting a potential alternative to the labor-intensive examination conducted by cardiologists. However, many existing approaches failed to adequately consider the temporal and channel dimensions when assembling features and ignored interpretability. And clinical theory underscores the necessity of prolonged signal observations for diagnosing certain ECG conditions such as tachycardia. Moreover, specific heart diseases manifest primarily through distinct ECG leads represented as channels. In response to these challenges, this paper introduces a novel neural network architecture for ECG classification (diagnosis). The proposed model incorporates Lead Fusing blocks, transformer-XL encoder-based Encoder modules, and hierarchical temporal attentions. Importantly, this classifier operates directly on raw ECG time-series signals rather than cardiac cycles. Signal integration begins with the Lead Fusing blocks, followed by the Encoder modules and hierarchical temporal attentions, enabling the extraction of long-dependent features. Furthermore, we argue that existing convolution-based methods compromise interpretability, while our proposed neural network offers improved clarity in this regard. Experimental evaluation on a comprehensive public dataset confirms the superiority of our classifier over state-of-the-art methods. Moreover, visualizations reveal the enhanced interpretability provided by our approach. HighlightsO_LIOur model extracts long-dependent features of ECG signals based on the Transformer-XL encoder. C_LIO_LIThe proposed network offers the improved interpretability. C_LIO_LIOur classifier achieves superior performance over other state-of-the-art methods. C_LI

bioengineering↗

bioRxiv2024

Genomic and transcriptomic characteristics of type VI secretion system in Klebsiella pneumoniae

The Type VI secretion system (T6SS) serves as a crucial molecular weapon in interbacterial competition and significantly influences cell-cell interactions. Various bacterial species utilize their T6SSs to execute a multitude of functions, dictated by their ecological niche. However, the characteristics of T6SS in clinical Klebsiella pneumoniae, a common opportunistic nosocomial pathogen, have not been fully elucidated. Here, we conducted a genomic analysis of 65 clinical K. pneumoniae isolates obtained from patients with varying infections. Genes encoding a T6SS cluster were present in all analyzed strains of K. pneumoniae. Strains of identical sequence type (ST) carried structurally and numerically identical T6SS. Our study also highlights the importance of selecting conserved regions in key T6SS genes for effective primer design in PCR identification. We then utilized the predominant ST11 K. pneumoniae HS11286 to investigate the effect of knocking out T6SS marker genes hcp or vgrG. Transcriptome analysis identified a total of 1,298 co-upregulated and 1,752 co-downregulated differentially expressed genes. Additionally, the absence of hcp or vgrG gene suppressed the expression of other T6SS-related genes within the locus I cluster. Pathway analysis showed that the {Delta}hcp mutant exhibited alterations in transport, establishment of localization, localization and cell processes. Furthermore, interbacterial competition experiments showed that hcp and vgrG are essential for competitive ability of ST11 K. pneumoniae HS11286. This study furthers our understanding of the genomic characteristics of T6SS in K. pneumoniae and suggested that the involvement of multiple genes in T6SS of strain HS11286. ImportanceGram-negative bacteria use T6SS to deliver effectors that interact with neighboring cells for niche advantage. K. pneumoniae is an opportunistic nosocomial pathogen that often carriers multiple T6SS loci, the function of which has not yet been elucidated. We performed a genomic analysis of 65 clinical K. pneumoniae strains isolated from various sources, confirming that all strains contained T6SS. We then used transcriptomics to further study changes in gene expression and effect upon interbacterial competition following knockout of key T6SS genes in ST11 K. pneumoniae HS11286. Our findings revealed the distribution and genomic characteristics of T6SS in clinical K. pneumoniae. This study also described the overall transcriptional changes in the predominant Chinese ST11 strain HS11286 upon deletion of crucial T6SS genes. Additionally, this work provides a reference for future research on the identification of T6SS in bacteria.

microbiology↗