Biology subjects

Jiang, L.

Publications and source records attributed to Jiang, L..

At least 55 records · Page 3Linked to original sources

bioRxiv2026

Rewiring of 3D Enhancer-Promoter Interactome Underlies Diabetic Endothelial Dysfunction

BackgroundDiabetic vascular complications are driven by endothelial dysfunction, yet the role of 3D genome organization in this process is unknown. We sought to define the alterations in chromatin architecture in diabetic endothelium and identify the key regulators involved. MethodsWe generated a high-resolution 3D epigenomic atlas of diabetic endothelial cells from mouse models and human subjects using H3K27ac HiChIP, complemented by ChIP-seq, ATAC-seq, and RNA-seq. A human cohort was used to assess protein expression in diabetic versus non-diabetic endothelial cells. To identify JUNB-interacting proteins, we performed rapid immunoprecipitation mass spectrometry of endogenous proteins (RIME), with protein-protein interaction validated by co-immunoprecipitation. Functional validation was performed using in vitro, ex vivo, and in vivo approaches, including endothelial-specific knockdown in a diabetic hindlimb ischemia model. ResultsMulti-omics profiling revealed extensive enhancer reprogramming in diabetic endothelium, with AP-1 binding motifs being consistently and selectively enriched in downregulated enhancers across three distinct diabetic models. Analysis of a human cohort confirmed significantly reduced JUNB protein levels in diabetic endothelial cells. We identified widespread disruption of JUNB-anchored enhancer-promoter interactions, which underlies transcriptional repression of key endothelial genes. RIME and co-immunoprecipitation established the E3 ubiquitin ligase RBBP6 as a direct JUNB interactor that promotes its polyubiquitination and proteasomal degradation in response to hyperglycemia. Human cohort analysis further showed reciprocal elevation of RBBP6 in diabetic endothelial cells. Either JUNB overexpression or RBBP6 knockdown restored enhancer-promoter connectivity, reactivated vasoprotective transcriptional programs, and rescued endothelial function. Critically, endothelial-specific knockdown of Rbbp6 in diabetic mice restored endothelium-dependent vasorelaxation and improved perfusion recovery after hindlimb ischemia, independent of systemic glucose levels. ConclusionsOur study unveils a novel mechanism whereby hyperglycemia induces enhancer reprogramming and disrupts endothelial 3D genome architecture through RBBP6-mediated degradation of JUNB. The RBBP6-JUNB axis is established as a crucial link between metabolic stress and epigenomic reprogramming in vascular disease, presenting a promising therapeutic target for diabetic vasculopathy.

genomics↗

bioRxiv2026

Functional Characterisation of Recombinant Proteins Using Ion Channel Switch Technology: A Label-Free, Wash-Free Platform for Biotechnological Applications

We present a rapid, label-free, and highly sensitive platform for characterising recombinant protein functionality using Ion Channel Switch (ICS) technology. This method enables precise evaluation of binding specificity, oligomeric state discrimination, and real-time analyte detection, addressing key challenges in protein engineering and bioprocess quality control. Using engineered single-chain variable fragments (scFv), ICS reliably distinguishes monomeric from multimeric forms, facilitates wash-free detection of analytes ranging from small molecules to larger biomolecules, and enables quantitative biosensing within seconds in real-time and continuous format. These capabilities establish ICS as a powerful tool for streamlining recombinant protein screening, with broad applications in diagnostics, therapeutic quality control, and automated bioprocess workflows.

bioengineering↗

bioRxiv2026

Stimulus-Driven Thermodynamic Shifts and Geometric Reorganization in Mouse Primary Visual Cortex

Efficient coding is essential for sensory systems to extract meaningful information from the environment. Here, we investigate how stimulus-driven thermodynamic shifts and geometric reorganization enable efficient population coding. Using wide-field calcium imaging, we simultaneously recorded neuronal activity across the entire mouse V1 under the presentation of structured stimuli and characterized neural dynamics spanning microscale neuronal connectivity, mesoscale thermodynamic states, and macroscale manifold geometry. We found that stimulus presentation reorganized neuronal couplings into increasingly modular subnetworks, driving a shift from near-critical dynamics toward a more ordered regime. This shift coincided with a compression of neural population activity onto low-dimensional manifolds aligned with stimulus features, thereby enabling efficient coding. Furthermore, mathematical derivations and in silico perturbation experiments confirmed that selective modulations of neuronal connectivity altered both critical temperature and manifold geometry, establishing a causal link from neuronal couplings to efficient coding. Collectively, our findings suggest a mechanistic bridge between statistical physics and neural geometry, providing new theoretical insights into how neural networks dynamically transition into more stable and efficient coding states in response to the environment.

neuroscience↗

bioRxiv2026

Reconciling Cooperativity Definition in PROTACs and Molecular Glues: Thermodynamic Dissection into PPI and Ligand Entropic Contributions

Douglass Cooperativity and Ciullis Cooperativity in induced-proximity systems, remains controversial with paradoxes such as path-dependent metrics and apparent universal negative Cooperativity. We noticed that in "partial-embedded" model, a substantial portion of giant ligand remains exposed outside and does not engage with the host proteins force field. It incurs an entropic cost due to the restriction of translational/rotational degrees of freedom. This large, mass-dependent unfavorable ligand entropy penalty normally shifts binding affinity to 104[~]108-fold. ITC thermodynamic cycles analysis confirmed the dramatic entropy loss among reaction pair. This reconciles the conflicting Cooperativity definitions, yielding true path-independent positive PPI Cooperativity from observed entropy loss subtracting ligand entropy penalty. ITC data showed rigid linkers appear superior to flexible linkers with respect to both oral bioavailability and safety profile in PROTAC design. "ligand entropy barrier wall/Cooperativity ladder" pair is not only impact induced-proximity systems but also constitute the physical basis for all biosystems.

biochemistry↗

bioRxiv2026

TREM2 agonist antibody rebuilds the resident synovial macrophage lining barrier in rheumatoid arthritis

Rheumatoid arthritis (RA) can be viewed as a disease of barrier failure, in which CX3CR1+/TREM2+ synovial tissue-resident macrophages that form the lining barrier over cartilage and bone become fragmented and disorganized. However, how to therapeutically rebuild this barrier--and how macrophage states transition during repair--remain unclear. We engineered TR-Ab19, a mouse-selective agonistic antibody against TREM2, as a precision tool to initiate and interrogate barrier repair in vivo. TR-Ab19 engages TREM2-linked downstream signaling and redirects synovial macrophages from Clec4d+ inflammatory/proliferative programs toward TREM2+CX3CR1+Aqp1+ barrier-like states, thereby rebuilding the lining barrier. Across collagen-induced arthritis (CIA) and serum-transfer arthritis (STA) models, TR-Ab19 reduces synovitis, preserves cartilage and bone microarchitecture, limits osteoclastogenesis, and attenuates systemic cytokines and B-cell abnormalities. Single-cell RNA-seq with trajectory and cell-cell communication analyses reveal a TREM2-dependent shift toward a barrier-dominant macrophage ecosystem. Together, these findings establish antibody-mediated reprogramming of resident synovial macrophages as a barrier-centered strategy for RA and provide a framework for instructing macrophage niches in chronic inflammation.

bioengineering↗

bioRxiv2026

S-SELeCT: A Human-Evolved Serine Integrase System for Efficient Large-Cargo Genome Integration

As a consequence of their sizes, many loss-of-function genetic mutations fall within large genes. A major gene-therapy tool that could be used to solve large swaths of the genetic diseases that result from these inherited mutations is large-fragment knock-in. I.e. instead of attempting to create separate treatments for each and every location that these mutations occur in, large groups of patients could be aided via a single safe-harbor integration of the full-length coding sequence. Towards this goal, we have created a set of early stage gene-editing enzymes that can help mediate large cargo integration at a safe harbor locus in human cells. When expressed in stable lines, our S-SELeCT (Site-Specific Large Cargo Targeting) integrase fusions can facilitate integration of a 10 kb plasmid at frequencies up to 32%, and when delivered transiently via plasmid transfection, we were able to achieve up to 13% knock-in. These are the first serine integrase enzymes that have been evolved fully in human cells, and the first to recognize an endogenous symmetric non-pseudosite - the first true human serine integrase attachment site. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=79 SRC="FIGDIR/small/702954v2_ufig1.gif" ALT="Figure 1"> View larger version (10K): org.highwire.dtl.DTLVardef@1c22676org.highwire.dtl.DTLVardef@16b171corg.highwire.dtl.DTLVardef@1ba4796org.highwire.dtl.DTLVardef@b1d91f_HPS_FORMAT_FIGEXP M_FIG C_FIG

genetics↗

bioRxiv2026

Mechanism study on lactic acid promoting intervertebral disc degeneration by regulating senescence and DNA damage of cartilage endplate stem cells

Intervertebral disc degeneration, a leading cause of low back pain with incompletely elucidated molecular mechanisms, was studied via integrated in vivo/vitro approaches. This study first reveals that lactic acid accelerates intervertebral disc degeneration by inducing cartilage endplate stem cells senescence and DNA damage, thereby activating the P16/P21/P53-centered senescence pathway. In a rat tail vertebra puncture-induced intervertebral disc degeneration model, degenerated discs exhibited increased lactic acid levels, narrowed intervertebral spaces, and disrupted nucleus pulposus structure (P<0.05). In vitro, 0/2/6/10 mM lactic acid dose-dependently suppressed cartilage endplate stem cells viability (10 mM group: 15.7% of the control), elevated intracellular reactive oxygen species (ROS, 2.8-fold relative to the control), induced G0 cell cycle arrest (10 mM group: 85.63%), reduced EdU-positive cells (8.62%), and increased {beta}-galactosidase-positive cells (10 mM group: 33.06%) and {gamma}-H2AX foci (all P<0.01).Molecularly, lactic acid significantly upregulated P16 (2.1-fold), P21 (3.1-fold), P53 (2.4-fold), and {gamma}-H2AX (1.8-fold). In vivo intervertebral disc injection confirmed a positive correlation between lactic acid concentration and intervertebral disc degeneration severity. This study clarifies lactic acids role in intervertebral disc degeneration via the "oxidative stress-cell cycle arrest-cellular senescence" axis, advancing understanding of intervertebral disc degeneration pathogenesis and providing a basis for targeted therapies against lactic acid metabolism.

cell biology↗

bioRxiv2026

Multi-Omics Reveals Activated Fibroblasts with Dual Functional Roles in Repair and Negative Barrier in the CD8+ T Cell Cytotoxic Niche for Lung Cancer Neoadjuvant Therapy

A major challenge in elucidating immune activation and tolerance is that single-omics technologies are inherently limited. Since single-cell transcriptomics lacks spatial information and spatial transcriptomics lacks resolution or depth, neither can adequately model the multidimensional tumor immune microenvironment (TiME) features. We present NICHE (Niche Integrated Cellular Heterogeneity Elucidator), an integrative multi-omics framework. By aligning physical cell-cell interactions with single-cell ligand-receptor (L-R) expression, NICHE leverages single-cell transcriptomics, spatial proteomics, and AI modeling to systematically decode the composition, spatial interactions, and communications within immune functional niches. To validate NICHEs capabilities, we applied it to human tonsil tissue. The framework successfully identified key structural and functional units and deeply elucidated the cell-cell interactions and molecular crosstalk within them. Furthermore, these results were validated through orthogonal methods, including single-cell spatial transcriptomics and multiplexed immunofluorescence, which confirmed the accuracy and reproducibility of our analyses. In non-small cell lung cancer (NSCLC) patients undergoing neoadjuvant immunotherapy, CD8+ T cell cytotoxic niches mediate tumor clearance with variable outcomes, to define the cellular and molecular drivers behind this functional spectrum, we utilized NICHE to analyze the TiME from patients with complete versus partial pathological response, both pre- and post-treatment. We found that neoadjuvant immunotherapy may induce the activation of CXCL12+, NECTIN2+, POSTN+, and COL6A1+ fibroblasts through the activation of cytotoxic T cells. Paradoxically, these fibroblasts support tissue repair but also establish an immunosuppressive niche that protects residual tumor cells, ultimately attenuating treatment efficacy. Our work establishes a multidimensional framework for dissecting dynamic immune activity, with direct implications for understanding tumor immunology and identifying novel therapeutic targets.

immunology↗

bioRxiv2026

Sox8 and Sox9 regulate differentiation and nuclear positioning of retinal Muller glia.

Temporal patterning of retinal progenitor cells governs the sequential generation of retinal cell types, with gliogenesis occurring late in development. Sox8 and Sox9, members of the SoxE transcription factor family, are highly expressed in late-stage retinal progenitor cells and mature Muller glia, yet their functional roles remain incompletely defined. Here we employed gain- and loss-of-function approaches, single-cell multiomic profiling, and injury models to investigate Sox8/9 function. Overexpression of SOX8 and/or SOX9 in early-stage retinal progenitor cells suppressed early-born cell fates and promoted photoreceptor generation, consistent with a role in late-stage temporal identity. Conversely, conditional deletion of Sox8 and/or Sox9 in late-stage progenitors did not impair Muller glia specification, but caused radial displacement of Muller glia nuclei into the outer retina and modest changes in glial gene expression. Loss of Sox8/9 in mature Muller glia modestly increased proliferation post-injury without inducing neurogenic competence. These findings suggest that Sox8/9 are dispensable for gliogenesis and repression of neurogenic competence, but are essential for proper laminar positioning and maturation of retinal Muller glia.

neuroscience↗

bioRxiv2025

COPS5 is Essential for Sertoli Cell Function and Male Fertility in Mice

The COP9 signalosome subunit 5 (COPS5) is a multifunctional protein that regulates ubiquitin-dependent processes. Global knockout of Cops5 is embryonically lethal, and while it is known to be vital in germ cells and testicular smooth muscle, its function in Sertoli cells, the key somatic supporters of spermatogenesis, remains entirely unknown. This study investigates the critical role of COPS5 within Sertoli cells. Using Sertoli cell-specific Cops5 knockout mouse models, we demonstrate that COPS5 is essential for maintaining male fertility. Sertoli-specific Cops5 ablation resulted in age-dependent male infertility, despite normal initial development. Mutants exhibited progressive testicular atrophy, oligoasthenospermia, and significantly reduced testis weight. Histology showed vacuolated, disorganized tubules devoid of germ cells and sperm. Crucially, COPS5 loss disrupted Sertoli cell polarity, evidenced by aberrant cytoplasmic mislocalization of the nuclear marker WT1 and detachment from the basement membrane. Integrity of the blood-testis barrier (BTB) was severely compromised, with discontinuous and punctate expression of the tight junction adaptor ZO-1. Intercellular communication was also impaired, shown by a stark reduction in Connexin 43 gap junction signals. Our findings establish that COPS5 is an indispensable intrinsic regulator of Sertoli cell function. Its loss disrupts cell polarity, BTB architecture, and gap junction communication, leading to failed support of spermatogenesis and consequently infertility. This work defines a novel and critical somatic function for COPS5 in male reproduction. We conclude that COPS5 is intrinsically required in Sertoli cells to maintain their polarity and BTB function, which are foundational for supporting germ cell development and ensuring male fertility. This identifies COPS5 as a novel, essential regulator within the testicular somatic compartment.

genetics↗

bioRxiv2025

Reconstructing developmental and disease progression with sample-level embeddings

Single-cell genomics is transformative for characterizing cellular heterogeneity, but many translational questions require comparing samples rather than individual cells. Typical analyses compare "case" and "control" groups, ignoring sample-level variation within them. Here we present scSLIDE, a framework that transforms each samples single-cell data into a compact profile describing where its cells fall in high-dimensional space. By comparing these density profiles, scSLIDE calculates embeddings to characterization variation across samples. Applied to COVID-19 infection, Alzheimers disease, and zebrafish embryogenesis, we show that scSLIDE can be used to cluster patients, reconstruct sample-level disease trajectories, and identify coordinated cellular programs across samples. We discover independent axes of infection and severity, a molecular disease progression that aligns with pathology-based estimates of neurodegeneration, and embryonic "pseudostages" varying across and within timepoints. In each case, we demonstrate how case-control analyses collapse rich biological variation into binary labels, and how sample-level embedding represents a powerful analytical alternative.

genomics↗

bioRxiv2025

From genomic decay to functional advantage: Trait-based evidence for long-term host residency of a next-generation coral probiotic

A key bottleneck in microbiome engineering is ensuring the long-term host association of introduced microbes. Selecting probiotic candidates based on evolutionary genomic decay signatures of emerging host dependency offers a potential solution. The Ruegeria strain B4 of the population MC10, identified by such signatures, has shown persistent colonization in corals in a companion study. Whether this persistence translates into a measurable host benefit compared to other coral-associated Ruegeria strains, and which mechanisms underlie such benefit, remained unknown. Here we directly compare the probiotic efficacy of MC10-B4 against two sympatric Ruegeria strains isolated from the same coral colony and mucus compartment, controlling for host genotype and microenvironment. MC10-B4 inoculation significantly increased heat stress tolerance in the coral model cnidarian Aiptasia (Exaiptasia diaphana strain H2), outperforming both sympatric control strains. To understand the mechanistic basis of this probiotic efficacy, we characterized the functional profile of MC10 using an integrated multi-omics approach. The genome of MC10 is enriched in genes associated with host-interaction, including siderophore-mediated iron acquisition and exopolysaccharide biosynthesis, which were phenotypically confirmed by detectable iron scavenging and enhanced biofilm formation. Following exposure to coral tissue extract, MC10-B4 underwent a coordinated motility-to-sessility proteomic reprogramming, downregulating flagellar motor components while upregulating flagellin and biofilm regulators. This response was distinct from its sympatric relatives, which instead mounted broad upregulation of nutrient acquisition systems. MC10-B4s functional profile, particularly its sensitivity to oxidative stress, contrasts with the traits typically favored in conventional probiotic screens. Our results move beyond the descriptive identification of a coral probiotic by providing initial mechanistic insight into traits associated with long-term host association and improved thermal performance. These findings validate an evolution-guided approach that prioritizes innate colonization potential over pre-defined laboratory functionalities, informing the rational design of durable probiotics.

microbiology↗

bioRxiv2025

Mechanism underlying the ultralow energy-consumption rapid ion dehydration for the high flux of KcsA potassium channels

High-flux and ultralow energy consumption (UEC) transport of biological and artificial ion channels has been widely reported [1-22]. However, there is a precondition for such transport: UEC rapid ion dehydration, which underlying mechanism is a remaining challenge. Here, by molecular dynamics (MD) simulations, we demonstrate that a K+ ion can transfer from the hydration water outside KcsA channel to the bound water in the channel without its hydration water accompanying, i.e., a tunneling-like motion, which provides a basis for the UEC dehydration of ions. In our simulations, a KcsA channel was divided into three regions: Cavity-1, Cavity-2 and the filter. As a K+ ion moves from Cavity-1 to Cavity-2, there occurs a resonant energy transfer to the ion from the filter-confined coherently oscillating ions, leading to a tunneling-like motion of the ion from the Cavity-1 to Cavity-2 water with no hydration shell accompanying and no influence on the Cavity-2 water. As the K+ ion further moves from Cavity-2 to the filter, the ion adjusts its hydration-shell water structure to coherence-resonantly couples with the filter-confined ions, leading to another tunneling-like motion to reach complete dehydration. These two consecutive processes constitute a "resonant tunneling" of the ion from Cavity-1 to the filter, as a basis for the UEC rapid dehydration. Our findings provide an understanding of the dehydration dynamics in biological channels and its relationship with the UEC high-flux, potentially promoting the development of artificial membranes design.

biophysics↗

bioRxiv2025

A neoantigen-microbead platform for personalized T cell cancer vaccination

Colorectal cancer (CRC) is a leading cause of cancer mortality and is characterized by a high tumor mutational burden, making it responsive to immunotherapy. We developed a bioinformatic and manufacturing pipeline for personalized cancer vaccines and evaluated it in the MC38 colon adenocarcinoma mouse model. Thirty-six high-scoring neoantigens (NAGs) were identified by exome and transcriptome analysis, produced as six purified polypeptides, and coupled to paramagnetic beads. Intralymphatic vaccination of C57BL/6 mice with NAG beads induced robust NAG-specific T cell and antibody responses, resulting in significant inhibition of MC38 tumor growth. Treated tumors displayed increased necrosis and CD8+ T cell infiltration. Compared with soluble peptides, bead-coupled antigens elicited superior protection. Studies in T cell-deficient and antibody-depleted mice confirmed that both CD4+ and CD8+ T cells mediated the antitumor effect. These findings highlight the potential of NAG bead vaccination as an effective immunotherapy for CRC.

cancer biology↗

bioRxiv2025

The 9p21.3 Coronary Artery Disease Risk Locus Modulates Vascular Cell-State Transitions via Enhancer-Driven Regulation of MTAP

The 9p21.3 locus is the strongest genetic association with coronary artery disease (CAD), yet its causal mechanisms remain unresolved. We map the regulatory architecture of 9p21.3 in disease-relevant vascular cells, identifying 12 enhancers within the CAD risk haplotype that respond dynamically to inflammatory and metabolic stress in fibroblasts and smooth muscle cells. These activated states are enriched for CAD heritability, implicating stress-responsive vascular wall cells in disease pathophysiology. Dense CRISPRi tiling integrated with fine-mapping and genomic constraint across >500,000 individuals nominates MTAP as the effector gene, with rs1537371 as a likely causal variant. Perturbation and multi-modal analyses show that MTAP loss induces pro-fibrotic and angiogenic programs and sensitizes vascular cells to TGF-{beta}-driven pathological transitions. Our findings reveal a vascular-specific enhancer network through which noncoding variation at 9p21.3 modulates CAD risk via MTAP--a previously unrecognized regulator of vascular remodeling located 269 kb from the risk haplotype. HighlightsO_LI9p21.3 CAD risk locus harbors 12 functional enhancers active in vascular wall cell types C_LIO_LICAD heritability is enriched in stressed vascular fibroblasts and smooth muscle cells C_LIO_LIHigh-resolution CRISPRi-MAC-seq maps 9p21.3 enhancer-gene and SNP-gene interactions C_LIO_LIMTAP identified as a causal effector gene regulated by 9p21.3 fine-mapped and constrained variants C_LIO_LIMTAP modulates TGF-{beta}-driven pathological vascular cell transitions C_LI

genomics↗

bioRxiv2025

Multimodal AI Decodes Extreme Environment Functional Dark Matter Beyond Homology

Functional annotation of proteins from extreme environments represents a major bottleneck for bioresource discovery, as a vast reservoir of functional dark matter defies existing homology-based methods. We demonstrate that environmental pressures impart conserved physicochemical energy signatures that co-determine protein function with sequence and structure. Here we developed ACCESS, a multimodal graph neural network employing hierarchical contrastive learning with a tailored label-sample co-embedding to fuse energy, sequence, and structural information and overcome homology scarcity. ACCESS surpasses state-of-the-art methods including BLASTp and CLEAN in annotating low-identity enzymes. Applied to extreme environmental metagenomics, we constructed a function map of extremophile enzymes to expand the biocatalyst library, pinpointed functionally critical residues to guide rational design, and enabled large-scale, function-based macro-evolutionary analyses. This paradigm transcends the limitations of homology, illuminating protein dark matter and accelerating the exploration of the biospheres functional diversity for applications in biotechnology and therapeutic development.

bioinformatics↗

bioRxiv2025

Integrated Bioinformatics analysis and Metabolomic Responses in finding novel therapeutic approach to treat viral myocarditis

BackgroundMyocarditis is one of the most common health problems in young people. Despite imaging techniques and endomyocardial biopsies advancing, there is still inadequate for myocarditis characterization. Some studies have shown that myocarditis is closely associated with mitochondrial dysfunction. Therefore, this study was aimed to identify mitochondrial-related biomarkers and gene regulatory networks in myocarditis and potential therapeutic targets. MethodsWe downloaded GSE95368 dataset from GEO to get myocarditis gene expression profiles, then used EdgeR and AI algorithm for bioinformatics analysis of DEGs functions. Established CVB3-induced mouse myocarditis model via intraperitoneal injection, and assessed energy metabolism differences using targeted metabolomics. CVB3 stimulus induced myocarditis in H9C2 cells. We assessed mitochondrial dysfunction (ATP, MMP) with commercial kits, MAPK8 release via ELISA, and MAPK8, p-PI3K, p-AKT levels by western blot. Furthermore, a total of 8 patients primarily diagnosed with myocarditis were enrolled, and levels of MAPK8 and CK in serum were detected. SP600125, an inhibitor of MAPK8, was administrated to CVB3-infected mice to study its potential protective effect in viral myocarditis. ResultsWe obtained 77 DEGs enriched in myocarditis. Analysis yielded 11 modules, MEpurple module genes linked to myocarditis progression were identified via WGCNA. MAPK8, NAMPT and ALB are associated with mitochondrial function. CVB3-infected mice showed cardiac inflammation and high MAPK8 expression in serum or heart tissues.The target metabolism results indicated altered central carbon metabolism distinguished CVB3 group from control, with higher D-Glucose-1-phosphate and D-Glucose-6-phosphate and lower L-Cystine, dCMP, IMP and Xylulose-5-phosphate levels. CVB3 treatment caused mitochondrial dysfunction in H9C2 cells (decreased ATP, MMP), and increased MAPK expression. Western blot showed MAPK8 consolidated the levels of p-PI3K and p-AKT. CK activity was notably higher in myocarditis patients than healthy individuals. MAPK8 levels in myocarditis patients serum also exceeded those in healthy individuals. Pearson analysis indicated that MAPK8 and CK may contribute to myocarditis progression via distinct mechanisms. In CVB3-infected mouse model with SP600125 treatment, cardiac inflammation and MAPK8, p-PI3k, p-AKT expression were reduced, confirming MAPK8s crucial role in viral myocarditis. ConclusionOur study identified MAPK8 as a key biomarker of myocarditis, and it may be a potential therapeutic target for myocarditis.

pathology↗

bioRxiv2025

Lactate dehydrogenase-induced DNA Topoisomerase 1 is a novel regulator of smooth muscle cell proliferation and remodeling in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) manifests by increased proliferation and survival of pulmonary vascular cells in small pulmonary arteries (PAs), PA remodeling and unresolved increase of PA pressure. PA smooth muscle cells (PASMCs) in PAH undergo metabolic shift to glycolysis resulting in over-production of lactate, hyper-proliferation, and apoptosis resistance, but the mechanisms are not completely understood. By using lung tissues and pulmonary vascular cells from PAH and non-diseased human lungs, unbiased proteomics, network analysis, and gain-and-loss of function approaches, we here report that up-regulation of lactate dehydrogenase A (LDHA)-lactate axis promotes PASMC-specific over-lactylation and consequent over-accumulation of DNA topoisomerase 1 (TOP1) in small remodeled PAs from PAH lungs, leading to the up-regulation of Akt-mechanistic target of rapamycin 1 (mTORC1) signaling, hyper-proliferation, and reduced apoptosis. Smooth muscle-specific LDHA knockdown prevented, and Ldha inhibitor oxamate reversed SU5416/hypoxia-induced TOP1 accumulation, pulmonary vascular remodeling, and pulmonary hypertension (PH) in mice. Pharmacological inhibition of TOP1 with indotecan suppressed Akt-mTORC1, decreased proliferation, induced apoptosis in human PAH, but not control PASMCs, and reversed PA remodeling, PH, and RV dysfunction in rats. Collectively, these data provide a novel mechanistic link from LDHA-driven lactate over-production through lactylation and overaccumulation of TOP1, to the up-regulation of Akt-mTORC1, hyper-proliferation and apoptosis resistance of PASMCs, pulmonary vascular remodeling, and PH, and identify TOP1 as a new potentially attractive molecular target for the remodeling-focused therapeutic intervention. Take-home messageLDHA-lactate-induced over-lactylation and overaccumulation of Topoisomerase 1 (TOP1) promotes pulmonary artery smooth muscle cell hyper-proliferation, remodeling, and pulmonary arterial hypertension, which are reversed by TOP1 inhibitor indotecan.

cell biology↗