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Zhang, W.

Publications and source records attributed to Zhang, W..

At least 163 records · Page 9Linked to original sources

L-cysteine inhibited the growth of Vibrio parahaemolyticus via increasing the ROS level

The emergence of multidrug-resistant Vibrio parahaemolyticus poses a severe threat to mariculture sustainability, highlighting the urgent need for eco-friendly antimicrobial agents. In this study, we demonstrated that L-Cysteine (L-Cys) functions as an inhibitor of V. parahaemolyticus, with a minimum inhibitory concentration of 7.5 mM. Microscopic observation and viability assays revealed that L-Cys compromises bacterial membrane integrity, ultimately leading to cell death. Further investigation indicated that the antibacterial effect is primarily attributed to the intracellular production of hydrogen sulfide (H2S) generated by L-Cys metabolism. Transcriptomic and biochemical analyses showed that L-Cys induced metabolic reprogramming by suppressing fatty acid {beta}-oxidation, one-carbon metabolism, and antioxidant enzymes. This disruption of redox homeostasis results in accelerated accumulation of reactive oxygen species (ROS). In addition to its antibacterial effect, L-Cys also effectively reduced the virulence factor of bacterial motility. Finally, L-Cys demonstrated broad-spectrum antimicrobial activity against other pathogenic Vibrio species, including V. alginolyticus and V. anguillarum. Our findings suggest that L-Cys is a promising antimicrobial agent inducing ROS to mediate membrane disruption, with the advantages of cost-effectiveness and environmental safety for controlling vibriosis. ImportanceVibrio parahaemolyticus is a significant pathogen in aquaculture and a common cause of seafood-borne gastroenteritis worldwide. The increasing prevalence of antibiotic-resistant strains of this bacterium highlights the need for alternative control agents. This study shows that L-cysteine (L-Cys) inhibits the growth of V. parahaemolyticus. Our data indicate that L-Cys is metabolized to produce hydrogen sulfide, which contributes to the accumulation of ROS and disrupts bacterial membrane integrity. Additionally, L-Cys reduces bacterial motility and shows inhibitory effects against other Vibrio species. These findings suggest that L-Cys may represent a useful agent for managing Vibrio infections in aquaculture settings.

microbiology↗

Cathepsin-dependent amyloid formation drives mechanical rupture of lysosomal membranes

Lysosomal membrane integrity is essential for cellular homeostasis, and its failure drives lysosomal storage disorders (LSD) and neurodegeneration. The dipeptide L-leucyl-L-leucine methyl ester (LLOMe) is widely used to model lysosomal damage, yet its mechanism remains poorly understood. The prevailing view holds that LLOMe polymerizes into membrane-permeabilizing peptide chains within the lysosomal lumen. Using cryo-electron tomography in cultured cells and primary neurons, we visualized the structural basis of LLOMe-induced lysosomal damage. We reveal that LLOMe forms amyloid structures within lysosomes that directly interact with and rupture the limiting membrane through mechanical stress. In vitro reconstitution confirms this amyloid-mediated mechanism. These findings establish a structural paradigm for lysosomal membrane disruption and provide insights into how disease-relevant protein aggregates, implicated in neurodegeneration and LSD, may compromise lysosomal integrity.

cell biology↗

Integration of early-stage cryopreservation and cell cycle modulation into a flexible kidney organoid differentiation system

Kidney organoids derived from human pluripotent stem cells (hPSCs) represent a promising platform for modeling nephrogenesis and renal diseases. However, conventional differentiation protocols are continuous and time-sensitive, limiting their scalability and reproducibility. Here, we developed a method to pause and resume organoid formation through cryopreservation at an early differentiation stage using a chemically defined formulation that maintains high post-thaw viability and differentiation potential. We further found that synchronizing hPSCs in the G1 phase with PD-0332991 enhanced post-thaw organoid formation and transcriptional fidelity, while G2 phase enrichment with Ro-3306 promoted the development of SLC12A3-positive distal convoluted tubules. The post-thaw organoids exhibited well-organized nephron architecture and function comparable to uninterrupted cultured controls. This platform proved effective for modeling BK polyomavirus (BKV) infection, drug-induced nephrotoxicity, and renal fibrosis. Together, our cryopreservation and cell cycle synchronization strategy provides a flexible, practical framework to advance organoid-based research and translation.

developmental biology↗

Habitat and Hydrodynamics Influence Coral Reef and Seagrass Microbial and Exometabolite Dynamics

Coral reef and seagrass ecosystems provide critical storm protection and economic revenue to tropical coastal communities. Effective monitoring and restoration strategies are essential given increasing impacts from climate change and human development. Microorganisms, and the metabolites they produce and consume, are key drivers of coastal ecosystem function. However, microbially-mediated metabolite recycling remains poorly understood, limiting its inclusion in conservation and restoration strategies. Here we examine how seawater exometabolites and microorganisms in coastal ecosystems vary in relation to habitat (seagrass or coral reef), temporal scales and hydrodynamics. We characterized benthic seawater from two St. John, U.S. Virgin Islands coral reefs (Yawzi and Tektite) and one seagrass meadow at dawn and mid-day over four consecutive days. Using quantitative metabolomics and SSU rRNA gene amplicon sequencing, we found that habitat served as the primary driver of exometabolite and microbial community composition, while daily changes and hydrodynamics strongly influenced system variability. Hydrodynamic modeling indicated offshore water intrusion at mid-day at Yawzi reef, likely driving exometabolite and microbial shifts towards oligotrophic taxa (e.g., SAR11, SAR86). In contrast, a high percentage of coastal source water in the seagrass habitat maintained stable exometabolite pools and supported diverse microbial communities. These findings demonstrate that coastal habitat and hydrodynamics strongly influence exometabolite and microbial assemblages, with lesser contributions from temporal changes. Integrating exometabolites, microorganisms, and hydrodynamics provides new insights into coastal ecosystem functioning useful for habitat monitoring and restoration strategies.

ecology↗

Glucokinase links metabolism and lineage plasticity in neuroendocrine prostate cancer via interaction with AKT1

Cancer cells frequently rewire their metabolism to sustain growth and survival under stress. Despite the critical role of metabolic adaptation in tumorigenesis, how specific metabolic enzymes regulate lineage plasticity remains unclear. Here, through FDG-PET imaging and transcriptomic analyses, we reveal markedly elevated glucose uptake in neuroendocrine prostate cancer (NEPC) and identify glucokinase (GCK) as a MYCN-induced metabolic enzyme. Beyond its metabolic role, GCK is indispensable for maintaining the neuroendocrine lineage of prostate cancer cells by establishing a functional circuit with AKT1 through reciprocal regulation--AKT1 binds and phosphorylates GCK at S373, whereas GCK phosphorylates AKT1 at S473. Pharmacological disruption of this AKT1-GCK axis suppresses tumor growth in NEPC mouse models and patient-derived xenografts. Altogether, our findings uncover both the metabolic and noncanonical kinase functions of GCK and establish the AKT1-GCK axis as a key link between metabolic reprogramming and neuroendocrine lineage transition in prostate cancer.

cancer biology↗

Genome writing and Targeted Delivery of the NKX6-3/ANK1 gene cluster and its Type 2 Diabetes GWAS Variants to Human iPSCs

Genome-wide association studies (GWAS) identified over 600 loci containing single-nucleotide polymorphisms (SNPs) associated with type 2 diabetes (T2D), most of which reside in non-coding regions. Among the set of T2D SNPs, linking causal genome variants to disease risk experimentally has remained a challenge; however, advances in synthetic mammalian genome writing techniques now enable the delivery of multiple haplotypes to human induced pluripotent stem cells (hiPSCs) to create a series of isogenic cell lines that can be differentiated and phenotyped in vitro. Here, to begin efforts in dissecting a T2D GWAS locus, we engineered an NKX6-3/ANK1 gene cluster knockout hiPSC line and introduced a landing pad facilitating the delivery of synthetic haplotype payloads. We built four haplotypes, including several that are not observed in nature, containing risk SNPs spanning the NKX6-3/ANK1 gene cluster using a method called "variant Switching Auxotrophic markers for Integration" (vSwAP-In), and integrated them precisely into hiPSCs. NKX6-3/ANK1 deletion blocked pancreatic progenitor and skeletal muscle differentiation, suggesting that NKX6-3 and ANK1 are required for early pancreatic and skeletal muscle development, and perhaps related to the existence of two nonoverlapping sets of SNPs in linkage disequilibrium that associate with the expression of the two adjacent genes. When NKX6-3/ANK1 T2D "Risk" haplotypes were reintroduced, skeletal muscle and pancreatic progenitor differentiation capabilities were restored. ANK1 expression was elevated in the ANK1 Risk and All-Risk haplotypes compared to the NKX6-3 Risk and Non-Risk haplotypes, establishing a functional experimental platform to examine risk SNP clusters in their native contexts. Overall, this work establishes a platform for the dissection of GWAS loci using synthetic haplotype genomics in hiPSCs. Significance StatementGenome-wide association studies have been used to identify disease-associated SNPs; however, most SNPs lie in non-coding regions, making functional experimentation difficult to perform. Using vSwAP-In, a yeast-based DNA variant-building method, and mSwAP-In, a mammalian genome engineering approach, we establish a platform for functional GWAS dissection in hiPSCs. This platform allows us to build DNA harboring virtually any combination of disease-risk SNPs, allowing for functional characterization of SNPs without the limitations of linkage disequilibrium. We demonstrate this approach using a Type 2 diabetes GWAS gene cluster, NKX6-3/ANK1.

genetics↗

Leveraging Human Pangenome for Improved Somatic Variant Detection

Somatic variant detection is technically challenging due to low variant allele fractions, the confounding presence of germline variation, and reference bias. Linear references such as GRCh38 miss sample-specific variation, causing misalignments and incorrect variant calls. Although telomere-to-telomere donor-specific assemblies (DSAs) accurately represent individual genomes, their application is limited by cost and technical barriers. Alternatively, the graph-based human pangenome provides a scalable framework to improve read alignment and perform genome inference. Here, we benchmarked somatic variant detection using GRCh38, graph-based pangenomes, and pangenome-inferred DSAs with a HapMap mixture dataset and the COLO829 melanoma cell line. Pangenome-guided alignment improves read mapping and somatic variant calling accuracy. Furthermore, personalized pangenomes partially reconstruct donor-specific genomic content, improving accuracy, reducing germline contamination, and enabling detection of events in loci absent or poorly represented in GRCh38. These findings demonstrate that graph-based and personalized pangenomes are effective strategies for enhancing somatic variant detection compared with GRCh38.

genomics↗

Pan-cancer tumor classification by a holistic tumor microenvironment atlas

The tumor microenvironment (TME) heterogeneity presents a major bottleneck to effective cancer immunotherapies. We address this by establishing a pan-cancer tumor classification system based on the holistic TME cellular components. First, using single-cell transcriptomes from 1,271 patients across 26 cancer types, we compile a TME cellular atlas, leading to the identification of recurrent cell states and multicellular modules across cancer types. Among these, we highlight a type I interferon (IFN-I)-related multicellular module, including IFIT1+ tumor-associated macrophages, as a critical contributor to immune-activation TMEs. From a holistic perspective, pan-cancer TMEs exhibit trichotomous patterns predominantly driven by T, myeloid, and stromal compartments. Leveraging fine-grained TME cellular composition, we further stratify all tumors into 10 stable groups. These groups display varying responses to immune checkpoint blockade (ICB), and each rationally selected therapeutic strategy specifically perturbs the corresponding expression signature. Our pan-cancer tumor classification scheme reveals the underlying patterns of TME heterogeneity and provides a framework for stratifying patients, guiding treatment selection, and developing novel therapeutic options.

cancer biology↗

Cross-tissue transcriptome-wide association study prioritizes druggable targets for hepatocellular carcinoma

BackgroundHepatocellular carcinoma (HCC) is known as the sixth most common cancer and the third leading cause of death related to cancer. While genome-wide association study (GWAS) has uncovered risk loci, mapping variants to causal genes and tissues is challenging. The aim of this study is to translate HCC GWAS signals from variants to genes and tissues to identify genetically regulated causal candidates and potential therapeutic targets. MethodsWe collected and integrated 12 benchmark GWAS summary statistics from different research including various areas and causes of HCC. We applied S-PrediXcan using GTEx 49 tissues to infer genetically regulated expression. Multiple testing was controlled using group-wise Benjamini-Hochberg FDR within tissues (primary, q[≤]0.05). For visualization, suggestive signals with p[≤]0.01 were highlighted; heatmaps display FDR-thresholder results, whereas other figures show the full distribution. We then performed cross-tissue prioritization, gene-trait network construction, gene set enrichment analysis (GSEA), and pathway enrichment. ResultsWe identified 422 significant gene-tissue associations (BH-FDR within tissue, q[≤] 0.05) regarding HCC, consolidating to 34 unique genes. Top tissues included breast mammary, left ventricle, and esophagus muscularis. Excluding established HCC loci (e.g., PNPLA3, TM6SF2, TERT, HSD17B13), we prioritized 32 druggable "novel" candidates, with top-ranked examples including DHCR24 and HLA-DPB1. ConclusionsCross-tissue TWAS integrating GWAS and GTEx models identifies genetically regulated genes associated with HCC, refines tissue specificity, and prioritizes plausible drug targets. This gene-centric framework complements variant-level GWAS and supports mechanism-guided prevention and therapy development.

bioinformatics↗

Ectopic engraftment of nociceptive neurons derived from hPSCs for pain relief and joint homeostasis

Chronic pain arises from the interplay of inflammatory signals that activate and sensitize nociceptors within injured tissues. Most analgesics fail clinically due to their mono-targeted mechanisms. Here, we apply human pluripotent stem cell-derived nociceptive neurons (hPSC-NNs) as therapeutic agents for osteoarthritis, targeting both pain and joint degeneration. We generated sensory neurons from hPSCs and identified CD200 as a nociceptor marker. Transcriptomic and functional profiling revealed that CD200highhPSC-NNs closely resemble human nociceptors, expressing pain-relevant receptors and ion channels. Strikingly, ectopic transplantation of CD200highhPSC-NNs into the knee joint of osteoarthritic mice reduced pain and promoted bone and cartilage repair, whereas CD200low cells exhibited no benefit. Mechanistically, human and mouse proteomics suggest that CD200highhPSC-NNs act as decoys by sequestering inflammatory ligands while secreting reparative factors in joint tissues. These findings uncover a fundamental role of nociceptors in tissue repair, providing a multi-targeted, disease-modifying strategy for OA and chronic pain. GRAPHIC ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/694733v1_ufig1.gif" ALT="Figure 1"> View larger version (70K): org.highwire.dtl.DTLVardef@15f0948org.highwire.dtl.DTLVardef@5a59bforg.highwire.dtl.DTLVardef@1ba4439org.highwire.dtl.DTLVardef@1d518d1_HPS_FORMAT_FIGEXP M_FIG C_FIG HIGHLIGHTSO_LIhPSC-derived nociceptors (hPSC-NNs) as Decoy Engraftment for Cellular Interception and Repair (DECIR) when transplanted into the knee joint, extending beyond conventional regenerative strategies C_LIO_LICD200 serves as a clinically actionable surface marker for the purification of hPSC-NNs C_LIO_LIEctopic grafting of CD200high hPSC-NNs delivers dual benefits, alleviating pain and modulating the neuro-immune environment within joint tissues C_LIO_LIProteomic analyses reveal that CD200highhPSC-NNs sequester inflammatory mediators and secrete reparative factors to support joint homeostasis C_LI

neuroscience↗

Genome editing for treatment of JAK2 V617F-driven myeloproliferative neoplasms

JAK2 V617F is a common haematological driver mutation and underlies most cases of myeloproliferative neoplasms (MPNs). Reducing variant allele frequency (VAF) is an important treatment goal, but no current treatment modalities fully and specifically inhibit mutant signalling. Thus, the consequences of V617F inactivation are unclear, including whether selective inhibition of V617F signalling will eradicate mutant cells due to oncogene addiction. Here, we describe an allele-selective CRISPR-Cas genome editing strategy that achieves selective and efficient JAK2 V617F inactivation in patient stem and progenitor cells. We show that JAK2 V617F heterozygous cells are not oncogene addicted and maintain viability and differentiation potential upon loss of their mutant allele. In contrast, homozygous mutant cells are eradicated upon deletion of both mutant alleles. Across in vitro, organoid, xenotransplantation and single-cell assays, selective deletion of V617F alleles reverts MPN hallmarks including erythroid clonogenicity, inflammatory gene expression signatures, as well as myelofibrosis and splenomegaly phenotypes in an in vivo xenograft model. Collectively, our results show that is it possible to revert heterozygous JAK2 V617F mutant cells to a normal phenotype and suggest that ex vivo genome editing of stem and progenitor cells may be a viable treatment option to achieve rapid and deep reductions in VAF.

cancer biology↗

Targeting Putrescine Homeostasis with Lactiplantibacillus plantarum PS128 to Mitigate Autism-like Behaviors in Fmr1 KO Mice

BackgroundAutism spectrum disorder (ASD) is biologically heterogeneous and has limited mechanism-informed interventions targeting core behavioral symptoms. Emerging evidence suggests that gut microbial metabolism shapes neurobehavioral outcomes, yet the specific metabolic pathways linking gut ecology to brain function remain incompletely understood. One candidate pathway is polyamine metabolism, which links microbial amino acid metabolism to host regulation and represents a plausible but underexplored contributor to ASD-related phenotypes. Notably, the psychobiotic Lactiplantibacillus plantarum PS128 has been reported to improve social behaviors in individuals with ASD, although the molecular basis for these effects is unclear. In this study, we used Fragile X mental retardation 1 knockout (Fmr1 KO) mice, a well-established ASD model, to investigate microbiota-dependent metabolic mechanisms underlying autism-like behaviors. ResultsWe found that autism-like behaviors in Fmr1 KO mice were associated with gut dysbiosis, impaired intestinal barrier integrity, disruption of the arginine-ornithine-polyamine pathway, and elevated putrescine in the prefrontal cortex (PFC). Supplementation with PS128 remodeled the gut microbiota, reduced inflammation- and disease-associated taxa, improved intestinal structure and permeability, and restored polyamine homeostasis. Targeted metabolomics revealed an increased PFC-to-serum putrescine ratio in KO mice, which was normalized following PS128 intervention. This correction was accompanied by reduced expression of polyamine transporters in the PFC, including ATP13A family members. Causal experiments supported a functional role for putrescine, as peripheral elevation of putrescine induced autism-like behaviors in wild-type mice, whereas pharmacological inhibition of putrescine synthesis ameliorated behavioral deficits in Fmr1 KO mice. ConclusionsThese findings identify putrescine metabolic dysregulation as a key contributor to autism-like phenotypes and support the existence of an ASD subtype defined by disruption of the arginine-ornithine-polyamine axis. Integrated multi-omics and causal perturbation analyses support a model in which microbiota-targeted intervention rebalances systemic polyamine regulation along the gut-brain axis, thereby improving ASD-relevant behaviors. Our work provides mechanistic evidence linking microbial metabolism to neurochemical homeostasis and highlights the translational potential of metabolic stratification in ASD. Graphical AbstractWe identify dysregulated microbiota-driven polyamine homeostasis as a causal contributor to autism-like behaviors in Fmr1 knockout mice. A psychobiotic intervention restores gut-brain metabolic balance and rescues social and repetitive behavioral deficits through coordinated microbial and host transport regulation. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/694366v2_ufig1.gif" ALT="Figure 1"> View larger version (53K): org.highwire.dtl.DTLVardef@e1e780org.highwire.dtl.DTLVardef@125a3baorg.highwire.dtl.DTLVardef@201228org.highwire.dtl.DTLVardef@1880650_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

Longitudinal Identification of Zebrafish Individuals by Deep Learning

The zebrafish (Danio rerio) is a critical vertebrate model organism in biomedical research. Accurate identification and longitudinal tracking of individual fish within cohorts enable linking genotype to complex phenotypes, essential for elucidating the molecular mechanisms underlying disease pathogenesis and trait formation. Nevertheless, the establishment of reliable long-term individual identification remains a significant challenge, primarily due to their diminutive size and minimal interindividual morphological variations. We developed ESC-IDNet, a dual-stage deep learning cascade architecture deployed on the FishIndivID platform (http://bioinfo.ihb.ac.cn/fishindivid), enabling high-precision identification. Trained and tested on [~]300,000 images from 450 zebrafish (31-122 dpf), our lateral body-based identification maintained >95% accuracy with updates only every 20 days, significantly outperforming dorsal head identification (requiring [~]13-day updates). Both views achieved 100% accuracy in 1-2 day tasks. ESC-IDNet surpassed alternatives in segmentation, alignment, feature extraction, and feature matching. This framework provides a robust, transferable paradigm for individual identification in fish species.

bioinformatics↗

Tryptophan Chemistry Driven by a Widespread Cytochrome P422 Enzyme Family

Tryptophan serves as a versatile biosynthetic precursor across living organisms. While heme-binding proteins (HBPs) mediate key reactions in tryptophan transformation, the full diversity of HBPs remains largely unexplored. Here, we developed the novel Cofactor-Integrative Structural Inspector (CISSspector) to systematically identify HBPs in the extensive extant microbial genomic sequence database, which revealed several uncharacterized HBP families. We experimentally characterized one of the most prominent families, the cytochrome P422 (formerly DUF6875) family, distributed throughout the prokaryotes and eukaryotes. Strikingly, we discovered that this enzyme family orchestrates four chemically distinct and biochemically unprecedented transformations, with regioselectivity, including N1-, C6-, and C7-hydroxylations and intramolecular C-S bond formations. Notably, the discovery of enzymes capable of Trp N1- and C7-hydroxylation addresses a long-standing gap in the natural enzyme arsenal. Structural analysis of the representative cytochrome P422 enzyme Mc170 revealed a structurally unique HBP fold in which conserved residues form a substrate "clamp" that positions the tryptophan indole ring for selective modification. Our work unveils a hidden enzymatic repertoire of HBPs, expands the known landscape of tryptophan metabolism, and establishes an artificial intelligence-augmented framework for discovering cryptic enzymes with broad implications for synthetic biology and natural product discovery.

biochemistry↗

Adult mice with neonatal-like T cell subsets exhibit increased susceptibility to Bordetella pertussis and influenza infection

Infants are significantly more susceptible to respiratory infection, often resulting in increased morbidity and hospitalization, and occasionally death. This susceptibility is partially explained by the developing nature of the thymus in human infants at, and for several months after, birth. However, the contribution of T cells produced in this thymic microenvironment to infant immune responses has received minimal investigation. Here, we utilized a previously described mouse model (Foxn1{Delta}/{Delta}) which exhibits a persistently immature thymus. Through further characterization, we have determined that adult Foxn1{Delta}/{Delta} mice retain some unique T cells observed in neonatal mice including CD8{beta}+ {gamma}{delta} T cells and CD8 T cells displaying a memory-like phenotype. For this reason, we assessed the potential of these neonatal-like T responses to two pathogens which disproportionately affect neonates, Bordetella pertussis (Bp) and influenza. Utilizing these infections, we demonstrate that T cells generated in an incompletely developed thymus fail to control or mount an effective response against Bp. We also observe that Foxn1{Delta}/{Delta} mice control acute influenza infection, a response which does not require IL-17. However, the Foxn1{Delta}/{Delta} mice fail to generate an influenza nucleoprotein (NP) specific CD8+ T cell response which is likely associated with their inability to fully clear the infection. Together, these data suggest that Foxn1{Delta}/{Delta} mice can be utilized to study the generation, function, and persistence of some unique T cells made in a neonatal-like thymus.

immunology↗

Rapid ecosystem collapse and biofilter formation following seabed methane leakage

Globally, vast amounts of methane are trapped within subseafloor gas hydrates. Recent evidence suggests that climate- and human-induced perturbations can destabilize gas hydrates and trigger methane release, yet the response of deep-sea ecosystems to these changes remains poorly understood. Here we show multi-year in situ monitoring of seabed ecosystem following methane leakage induced by hydrate exploration activities. Within just two years, benthic microbial and eukaryotic diversity in the affected areas declined significantly, while microbial and macrofaunal abundance increased. Integrated geochemical and omics analyses reveal the rapid successional shift of seabed ecosystem to a novel chemosynthetic system. Aerobic methanotrophs (Methyloprofundus) co-established with unexpectedly fast growing anaerobic methanotrophic archaea (ANME-3), accompanied by a rapid recruitment of opportunistic polychaetes that bioirrigated the seabed to >50 cm depths. The active animal-microbe interactions sustained exceptionally high rates of methane oxidation that utilized diverse electron acceptors. We demonstrate that methane hydrate destabilization can trigger rapid collapse of native seabed ecosystem while driving the formation of an effective methane biofilter consuming this potent greenhouse gas much faster than previously estimated. Understanding seabed ecosystem response and feedback is critical for predicting benthic methane cycling under ongoing global change and for developing sustainable strategies for methane hydrate resource management.

ecology↗

Synthetic Modular Cyanobacterial Consortium Enables Carbon-Negative Production of Glycerol and Derivatives

Cyanobacteria offer a direct route for converting solar energy and CO2 into valuable chemicals, yet the metabolic burden of complex heterologous pathways often limits their productivity and stability. Here, we present a modular co-culture strategy that uses glycerol as an efficient mediator metabolite to link cyanobacterial carbon fixation with downstream bioconversion. We first engineered Synechococcus elongatus UTEX 2973 (Syn2973) for high-level glycerol biosynthesis by optimizing synthase selection, eliminating competing pathways, and improving CO2-supply conditions, achieving a production of 14.53 g{middle dot}L-1. In parallel, we constructed glycerol conversion modules in Syn2973 and Gluconobacter oxydans enabling production of 1,3-propanediol (1,3-PDO), 3-hydroxypropionic acid, and dihydroxyacetone, with exogenous glycerol yielding up to 30.07 g{middle dot}L-1 1,3-PDO. Integrating the two modules resulted in a fully autotrophic co-culture that produced all three target chemicals directly from CO2, including semi-continuous 1,3-PDO production at 6.02 g{middle dot}L-1{middle dot}day-1, corresponding to a net carbon fixation efficiency of 3.43 kg CO2 eq/kg 1,3-PDO.

synthetic biology↗

The Human Hippocampus Is Involved in Auditory Short-Term Memory Trace Formation

The human hippocampus has been claimed to play an important role in long-term memory, or episodic memory, but its contribution to short-term memory remains debated. Here, we demonstrate human hippocampal involvement in auditory short-term memory (ASTM) trace formation. We used a classic oddball paradigm and intracranial recordings across various human brain areas. High frequency activities evoked by deviant stimuli in subjects indicate the generation of ASTM trace. Analysis of auditory response latencies across the hippocampus, insula, and temporal, parietal, and frontal lobes revealed the early processing of ASTM trace at a pre-attention stage. Granger causality analysis further showed that ASTM trace processing engages hierarchical cortical areas and clarified their interactions. Bottom-up signals flow from the insula and auditory temporal regions to the frontal lobe early on, followed by top-down information from the frontal lobe to the hippocampus, inferior temporal lobe, and insula at a later pre-attentive stage. Critically, Bayesian model selection of dynamic causal modeling revealed that deviant stimuli selectively enhanced the effectiveness of top-down connections to the hippocampus, thereby facilitating ASTM trace formation. These results provide compelling evidence that the human hippocampus contributes to auditory short-term memory at a pre-attention stage and suggests a challenge to entrenched beliefs in the classification of memory systems.

neuroscience↗