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Biomedical subjects

Liang Zhang

Publications and source records attributed to Liang Zhang.

5 recordsLinked to original sources

Magnetite facilitates phage-bacteria interactions and phage-associated metabolic coordination for medium-chain fatty acid biosynthesis under ammonia stress.

Medium-chain fatty acid (MCFA) production from waste activated sludge (WAS) is considered to rely on the syntrophic interactions among distinct functional microorganisms. Whether phages represent an overlooked ecological component involved in MCFA biosynthesis remains unclear. MCFA production is often inhibited by high total ammonia nitrogen (TAN). Conductive materials have been proposed as effective strategies to enhance or recover MCFA production under TAN stress. Therefore, the inhibition-recovery system could provide a useful framework for investigating whether viral ecological responses are associated with MCFA-related metabolic processes. In this study, magnetite (Fe3O4) was selected as the recovery strategy of MCFA production under TAN stress. Results showed that a total of 3915 vOTUs and 118 metagenome-assembled genomes were recovered from the anaerobic bioreactors subjected to three conditions: Control (without TAN stress), TAN stress, and TAN stress with Fe3O4 presence. Under high TAN environment (∼5 g/L), MCFA production reduced by 49% (1.3 g COD/L) in comparison to that without high TAN stress. The ecological coupling between temperate phages and MCFA-related bacterial hosts was weakened, accompanied by substantial decreases in the abundance and transcriptional abundance of phage-associated auxiliary metabolic genes (AMGs) related to MCFA synthesis (e.g., fatty acid biosynthesis, acyl-chain metabolism). In the presence of Fe3O4 (i.e., 10 g/L), MCFA production was four and two times higher than those with and without high TAN stress. In addition to enhanced phage-bacteria ecological coupling and increased the abundance and transcription of AMGs related to MCFA formation, Fe3O4 increased the abundance and expressions of electron-transfer-related AMGs (e.g., cbb3-type cytochrome c oxidase, type IV pilus assembly genes) and QS-related LuxR-family and HTH-type regulators, indicating that such indirect pathway could be largely overlooked during MCFA synthesis. This is also the first-time reporting that phages could represent an ecological layer responsive to iron oxide. Analyses of publicly available metagenomes collected from MCFA-oriented anaerobic systems further confirmed that phages could be broadly associated with the metabolic processes involved in MCFA biosynthesis. Taken together, this study reveals that phages could serve as an overlooked ecological layer associated with MCFA metabolism and provide a viral-ecology perspective for understanding TAN inhibition and iron oxide-mediated recovery during WAS-to-MCFA bioconversion.

Ammonia inhibition

ATF4-histone 2-hydroxyisobutyrylation feedback loop drives sepsis-induced inflammation.

BACKGROUND AND PURPOSE: The role and mechanisms of lysine 2-hydroxyisobutyrylation (Khib) in the acute inflammatory phase of sepsis remain unclear. We investigated the function and underlying mechanisms of histone H4 lysine 5 2-hydroxyisobutyrylation (H4K5-hib) in sepsis-induced inflammation in vivo and in vitro. EXPERIMENTAL APPROACH: Acute sepsis was induced by caecal ligation and puncture (CLP) in mice, and inflammatory responses were modelled in lipopolysaccharide (LPS)-stimulated macrophages. CUT&Tag-seq was used to identify genomic targets associated with H4K5-hib and activating transcription factor 4 (ATF4). Immunofluorescence, Western blotting, qPCR, dual-luciferase assays, and ELISA were performed to investigate the underlying mechanisms. KEY RESULTS: H4K5-hib levels were increased in macrophages during the acute inflammatory phase of sepsis. LPS stimulation enhanced H4K5-hib enrichment at the ATF4 promoter, thereby promoting ATF4 transcription. Inhibition of EP300-mediated 2-hydroxyisobutyrylation or mutation of H4K5 abolished ATF4 activation. Increased H4K5-hib activated the ATF4/NLRP3 signalling axis, promoting inflammasome assembly and amplifying inflammatory responses. ATF4 directly bound to the EP300 promoter and enhanced its transcription, forming a positive feedback loop that further increased H4K5-hib levels. In CLP-induced sepsis, pharmacological inhibition of EP300 or ATF4 reduced H4K5-hib levels and suppressed NLRP3 inflammasome activation. CONCLUSION AND IMPLICATIONS: These findings reveal a previously unrecognized epigenetic mechanism underlying sepsis-induced inflammation and identify the EP300/ATF4/H4K5-hib positive feedback loop as a potential therapeutic target for sepsis.

Animals

Personalized functional topography-based multisite brain age prediction modeling reveals divergent neurodevelopment in major depression.

Major depressive disorder (MDD) is associated with widespread alterations in functional brain networks across the lifespan. However, heterogeneity in atypical brain development among patients with MDD remains largely uncharacterized. Using a multisite resting-state functional MRI dataset consisting of 1,105 MDD patients and 1,065 healthy controls, we constructed a harmonized multicenter brain age prediction model based on individualized functional topography and identified two patient subgroups with positive or negative brain age gaps (BAGs). In patients with a positive BAG (BAG+), expansion of the salience network (SAL) into the dorsolateral prefrontal and ventrolateral prefrontal cortices, in addition to contraction of the sensorimotor and dorsal attention networks (DAN), contributes to accelerated brain aging. Conversely, in the negative BAG (BAG-) group, SAL expansion into the orbitofrontal cortex (OFC) and contraction of the visual and sensorimotor networks (SMN) were linked to delayed brain development. These subgroups also exhibited distinct neurodevelopmental trajectories. Clinically, BAG+ patients showed stronger associations between higher-order network topography and mood symptoms, whereas BAG- patients exhibited links between visual/default mode network topography and insomnia. At the molecular level, both groups showed enrichment of genes related to synaptic signaling but displayed distinct expression patterns and divergent expression trajectories in key neurodevelopmental gene sets. Notably, antidepressant treatment modulated the brain in ways that were specific to each subgroup. These findings reveal heterogeneous neurodevelopmental profiles in MDD with distinct biological and clinical signatures, offering insights into personalized precision medicine for this disorder.

Humans

Stage-dependent proteomic alterations in aqueous humor of diabetic retinopathy patients based on data-independent acquisition and parallel reaction monitoring.

BACKGROUND: Diabetic retinopathy (DR), a microvascular complication of diabetes mellitus (DM), represents the predominant cause of preventable vision loss in working-age populations globally. While the pathophysiological mechanisms underlying DR progression remain incompletely understood, our study employs comprehensive proteomic profiling of aqueous humor (AH) to identify stage-specific biomarkers and therapeutic targets in type 2 diabetes mellitus (T2DM) patients across DR progression. METHODS: Utilizing data-independent acquisition (DIA) mass spectrometry, we quantified AH proteomes in a discovery cohort comprising 24 subjects: 18 T2DM patients stratified by DR severity [6 non-DR, 6 non-proliferative DR (NPDR), 6 proliferative DR (PDR)] and 6 cataract controls without diabetes (non-DM). Validation cohort analysis (including 10 AH samples in each group) was performed using parallel reaction monitoring (PRM) strategy for verification of target proteins. Comprehensive bioinformatics analyses included gene set enrichment analysis (GSEA), weighted gene co-expression network analysis (WGCNA), Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis, protein-protein interaction (PPI) network construction, receiver operating characteristic (ROC) curve analysis, and ConnectivityMap (Cmap)-based drug prediction. RESULTS: Proteomic profiling identified 739 quantifiable AH proteins (62% extracellular) with clear separation among the four clinical stages in the discovery cohort. GSEA uncovered altered expression of proteins mainly related to complement and coagulation cascades, folate metabolism, and the selenium micronutrient network in patients with DR. WGCNA-derived protein modules yielded 83 PRM-validated targets, including 5 hub proteins differentiating NPDR from non-DR and 33 hub proteins showed significant upregulation in PDR versus NPDR comparison. Clinical correlation analysis identified F2, FGG, FGB, RBP4, AMBP, VTN, C8A, CPB2, and C2 associated with clinical traits. C6, FAM3C, SPP1, and JCHAIN levels were altered post-anti-VEGF treatment. Pharmacological prediction identified potential therapeutic compounds, including perindopril, triciribine, and XAV-939 for NPDR, and topiramate, triciribine, and vecuronium for PDR. CONCLUSION: This study established a comprehensive AH proteomic signature of DR progression, offering insights into the pathogenesis of DR and highlighting potential biomarkers and novel therapeutic targets.

Humans

Phase separation of hnRNPA1 and TERRA regulates telomeric stability.

Telomeres are the complexes composed of repetitive DNA sequences and associated proteins located at the end of chromatin. As a result of the DNA replication ending issue, telomeric DNA shortens during each cell cycle. The shelterin protein complex caps telomeric ends and forms a high-order protein-DNA structure to protect telomeric DNA. The stability of telomeres is critical for cellular function and related to the progression of many human diseases. Telomeric repeat-containing RNA (TERRA) is a noncoding RNA transcribed from telomeric DNA regions. TERRA plays an essential role in regulating and maintaining the stability of telomeres. Heterogeneous nuclear ribonucleoproteins (hnRNPs) are RNA-binding proteins associated with complex and diverse biological processes. hnRNPA1 can recognize both TERRA and telomeric DNA. Previous research reported that hnRNPA1, TERRA, and POT1, a component of the shelterin complex, work coordinately and displace replication protein A from telomeric single-stranded DNA after DNA replication, promoting telomere capping to preserve genomic integrity. However, the detailed molecular mechanism has remained unclear for >20 years. Here, our study revealed the molecular structure through which the hnRNPA1 UP1 domain interacts with TERRA and identified critical residues on the interacting surface between UP1 and TERRA. Furthermore, we proved that nucleic acids significantly increase the phase-separating ability of hnRNPA1, while disrupting the UP1-TERRA interaction extraordinarily affects hnRNPA1 droplet formation both in vitro and in vivo. Taken together, these data reveal the molecular mechanism of the phase separation of hnRNPA1 and TERRA and the potential contribution of the droplets to maintaining genomic stability.

Heterogeneous Nuclear Ribonucleoprotein A1