Copper is an essential trace element involved in various physiological processes. However, excessive copper levels in cells trigger cellular toxicity and "cuproptosis". Nevertheless, its role and the underlying mechanism...Copper is an essential trace element involved in various physiological processes. However, excessive copper levels in cells trigger cellular toxicity and "cuproptosis". Nevertheless, its role and the underlying mechanisms of cuproptosis in colorectal cancer (CRC) therapies remain largely unexplored. Unexpectedly, we find that copper triggers the translocation of a copper-binding protein, 4-hydroxyphenylpyruvate dioxygenase (HPD), into mitochondria via the TOMM40-TIM23 complex, in cooperation with HSP70 and HSP90. Upon arrival at the mitochondria, HPD interacts with dihydrolipoamide S-acetyltransferase (DLAT), thereby inducing cuproptosis. Furthermore, we identify Dacomitinib as an HPD-targeting cuproptosis inducer, which triggers CRC cuproptosis by enhancing the interaction between HPD and DLAT. Consequently, the combination of Dacomitinib and copper ionophores synergistically alleviates CRC tumorigenesis both in vitro and in vivo. In summary, our findings reveal that HPD, as a copper-binding protein, facilitates cuproptosis in cancer cells through its moonlighting function. This mechanism represents a therapeutic target for enhancing cuproptosis.
Human placental development is essential for pregnancy but remains mechanistically obscure because early post-implantation tissues are inaccessible. Here, we establish a rotational trophoblast organoid platform that reca...Human placental development is essential for pregnancy but remains mechanistically obscure because early post-implantation tissues are inaccessible. Here, we establish a rotational trophoblast organoid platform that recapitulates selected morphogenetic features shared with early trophoblast development, including spontaneous syncytiotrophoblast (STB) differentiation and progressive fusion of lacuna-like cavities. Integrated multi-omic analyses associate this architecture with a biomechanical balance between attenuated YAP activity and peripheral CREB activation, with GCM1 stabilizing trophoblast chromatin state and POLQ supporting genome maintenance in rapidly expanding progenitors. The organoids display autonomous endocrine activity, induce an endometrial epithelial state consistent with metabolic activation, and can generate extravillous trophoblasts that directionally engage endothelial networks. This platform provides a framework for studying placental morphogenesis and tissue interactions relevant to pregnancy complications.
Son GY, Bomfim GHS, Xu F
… +14 more, Thomas SC, Rosenberg K, Kim T, Rice E, Budjav E, Jones R, Wang YH, Mitaishvili E, Feske S, Jones DR, Rosado-Olivieri E, Rothermel BA, Saxena D, Lacruz RS
Individuals with Down syndrome (DS) produce less saliva for unknown reasons resulting in chronic periodontal disease with systemic detrimental effects. Using the (Dp(16)1Yey) mouse model of DS we define the molecular mec...Individuals with Down syndrome (DS) produce less saliva for unknown reasons resulting in chronic periodontal disease with systemic detrimental effects. Using the (Dp(16)1Yey) mouse model of DS we define the molecular mechanisms of hyposalivation and potential links to periodontal disease. We show that Dp(16)1Yey mice produce less saliva and have a higher immune burden in the salivary glands. We demonstrate that store operated calcium entry (SOCE), required for saliva secretion, is deficient in the salivary glands of Dp(16)1Yey mice. SOCE is also reduced in iPSCs from an individual with DS. We show that the oral and gut microbiomes of Dp(16)1Yey mice have abundant succinate-associated microbes and high succinate levels in the serum. We highlight associations between altered Ca handling and hyposalivation, dysbiosis, and periodontal disease in DS. The administration of pilocarpine in Dp(16)1Yey mice increased salivation, suggesting that cholinergic agonists might be useful to improve the oral health of individual with DS.
Enteric organs display the intrinsic ability to generate slow-wave potentials, rhythmic electrochemical events regulating gastrointestinal motility. In mammals, slow waves arise from the pacemaker activity of interstitia...Enteric organs display the intrinsic ability to generate slow-wave potentials, rhythmic electrochemical events regulating gastrointestinal motility. In mammals, slow waves arise from the pacemaker activity of interstitial cells of Cajal, which, by recruiting visceral muscles, ultimately lead to peristalsis, a movement pattern conserved across species. Here, we identify a motility program in Drosophila distinct from peristalsis that generates strong whip-like midgut contractions. This activity, here named superstalsis, is associated with specific physiological conditions and involves longitudinal visceral muscle activation. We find that both peristalsis and superstalsis involve TMEM16 family members, with peristalsis relying on myogenic activity mediated by Subdued, the Drosophila ortholog of ANO1/TMEM16A, whereas superstalsis depends on a separate non-neuronal pathway. As fasting and bacterial infections cause specific changes in the intestinal motility profiles in vivo, we propose that the gut can autonomously alter the peristalsis/superstalsis balance to efficiently respond to diverse pathological and homeostatic events.
Severe asthma frequently manifests as a neutrophilic phenotype associated with dysregulated Th17 cell response, yet the molecular mechanism regulating Th17 cell-driven pathology remain poorly defined. Here, we identified...Severe asthma frequently manifests as a neutrophilic phenotype associated with dysregulated Th17 cell response, yet the molecular mechanism regulating Th17 cell-driven pathology remain poorly defined. Here, we identified histone deacetylase (HDAC) 10 as a critical regulator of Th17 cell differentiation in severe asthma. HDAC10 expression in CD4 T cells was upregulated in asthmatic mice and patients with asthma. CD4 T cell-specific deletion of Hdac10 attenuated neutrophilic airway inflammation by dampening Th17 cell differentiation and subsequent IL-17A secretion. Mechanistically, HDAC10 directly bound to signal transducer and activator of transcription 3 (STAT3) and deacetylated it at lysine 631 (K631) in Th17 cells, a post-translational modification essential for Il-17a transcription and subsequent neutrophilic airway inflammation. Importantly, pharmacological inhibition of HDAC10 abrogated Th17 cell response and neutrophilic airway inflammation. Together, our findings reveal an unrecognized role for HDAC10 in governing Th17 cell pathogenicity, highlighting HDAC10 as a promising therapeutic target for severe asthma.
Gram-negative bacteria rely on an asymmetric outer membrane for barrier integrity, with phospholipids confined to the inner leaflet and lipopolysaccharide or lipooligosaccharide (LOS) forming the outer leaflet. Although...Gram-negative bacteria rely on an asymmetric outer membrane for barrier integrity, with phospholipids confined to the inner leaflet and lipopolysaccharide or lipooligosaccharide (LOS) forming the outer leaflet. Although these glycolipids were long considered essential, recent findings challenge this view. Here, using Acinetobacter baumannii, we identify lipid asymmetry as a structural checkpoint controlling access to LOS-independent survival. Disruption of phospholipid transport and degradation destabilizes membrane balance, creating a permissive state that enables the emergence of LOS-deficient, colistin-resistant variants. Lipidomic and transcriptomic analyses reveal coordinated envelope remodeling, including altered peptidoglycan synthesis and enhanced envelope trafficking. Loss of LOS coincides with repression of PBP1A, and maintaining its activity blocks adaptation. We propose a three-state model-basal, permissive, and adapted-that explains how envelope architecture governs antibiotic resistance and membrane remodeling.
The human gut is shaped by environmental factors, producing distinct microbial communities. Indigenous individuals practicing traditional lifestyles often harbor more diverse microbiota, with taxa often absent in industr...The human gut is shaped by environmental factors, producing distinct microbial communities. Indigenous individuals practicing traditional lifestyles often harbor more diverse microbiota, with taxa often absent in industrialized people. However, little engagement has occurred with American Indian communities in North America who experienced forced relocation and dietary programs during colonization. Here, shotgun metagenomics profiled the gut microbiome of people from a Northern Plains tribe (NPT) reservation in comparison to 12 global populations engaged in traditional, agrarian, or industrialized lifestyles. Analysis of the 532 samples revealed that the NPT microbiota exhibited greater bacterial and archaeal diversity than industrialized populations but reduced diversity compared to global traditional and agrarian populations. Relative to the general United States population, NPT microbiomes encoded more virulence factor and microbial defense genes and fewer CAZyme-encoding genes. These findings suggest that the NPT gut microbiome is in transition between lifestyles associated with global Indigenous and industrialized populations.
Neonatal meningitis-causing Escherichia coli (NMEC) is a primary etiological agent of neonatal meningitis. Inflammatory cell death triggered by NMEC infection has been implicated as a critical determinant of blood-brain...Neonatal meningitis-causing Escherichia coli (NMEC) is a primary etiological agent of neonatal meningitis. Inflammatory cell death triggered by NMEC infection has been implicated as a critical determinant of blood-brain barrier (BBB) disruption and neuroinflammation. However, the mechanisms underlying inflammatory BBB breakdown and the propagation of inflammation within the neuroinflammatory milieu remain poorly understood. Here, we show that brain endothelial cells (ECs) undergo GSDMD-dependent pyroptosis in response to NMEC infection. Through integrated spatiotemporal single-cell transcriptomic, epigenomic, and proteomic analyses, we identify Gbp5 as a key regulator of pyroptosis in brain ECs. Moreover, we uncovered a homeostasis-to-inflammation transition in both ECs and microglia (MG), whereby pyroptotic ECs promote microglial pyroptosis via Angptl4-Sdc4 signaling. This intercellular communication establishes a "pyroptosis cascade" between BBB ECs and microglia in the central nervous system (CNS), providing mechanistic insight into inflammatory BBB disruption and revealing potential therapeutic targets within the CNS immune microenvironment.
Bacteriophages are emerging as modulators of plant-microbe interactions and promising biocontrol agents against bacterial plant pathogens. In this study, we investigate the tripartite interaction between Arabidopsis thal...Bacteriophages are emerging as modulators of plant-microbe interactions and promising biocontrol agents against bacterial plant pathogens. In this study, we investigate the tripartite interaction between Arabidopsis thaliana, Xanthomonas campestris pv. campestris (Xcc), and the virulent phage Seregon. Parallel transcriptomic profiling shows that application of a single-phage treatment does not eradicate Xcc but strongly mitigates disease symptoms, restoring plant growth within 14 days post-inoculation. Phage-mediated protection is further associated with reduced plant immune activation, including lower jasmonate-related responses and reactive oxygen species levels, confirmed using nuclear reporter lines and histochemical staining. In parallel, Xcc shows reduced expression of key virulence-associated genes, including type III secretion system components, effectors, and flagella biosynthesis genes. Notably, phage treatment does not promote substantial resistance emergence in planta, contrasting with in vitro conditions. Together, our findings show that phage biocontrol can enhance plant resilience by modulating both host immunity and pathogen behavior.
Protease-activated receptor 4 (PAR4) mediates platelet activation during thrombosis and represents a promising target for antiplatelet therapies. This receptor is activated when serine proteases cleave its N terminus, ex...Protease-activated receptor 4 (PAR4) mediates platelet activation during thrombosis and represents a promising target for antiplatelet therapies. This receptor is activated when serine proteases cleave its N terminus, exposing a self-activating tethered ligand. Here, we report the cryo-electron microscopy (cryo-EM) structure of self-activated PAR4 in complex with G heterotrimers. The tethered ligand binds a shallow pocket, forming limited interactions with the transmembrane bundle and adopting a lateral binding pattern distinct from other PAR subtypes. It activates PAR4 by propagating conformational rearrangements to conserved micro-switches, triggering helix 8 rotation. G signaling is uniquely modulated by shallow engagement of the wavy hook, which disrupts its interaction with the DRY motif. Molecular docking demonstrates that the selective agonist PAR4-AP enhances activation through additional hydrophobic contacts and a stabilizing salt bridge, revealing the determinants of subtype selectivity. These findings provide mechanistic insights into PAR4 signaling, laying a foundation for the discovery of PAR4-targeted antithrombotic drugs.
Yang T, Xu YR, Li S
… +12 more, Bellier JP, Tao Y, Francis AE, Stern AM, Jin S, Ostaszewski BL, Lawton TL, Pradier L, Reczek D, Lemere CA, Walsh DM, Selkoe DJ
Immunotherapy against amyloid β-protein (Aβ) for Alzheimer's disease (AD) has been widely approved. Breakthrough disease-modifying treatments such as lecanemab and donanemab are often followed by drugs with improved effi...Immunotherapy against amyloid β-protein (Aβ) for Alzheimer's disease (AD) has been widely approved. Breakthrough disease-modifying treatments such as lecanemab and donanemab are often followed by drugs with improved efficacy. By immunizing Trianni mice with aggregated synthetic Aβ, we obtained B28, a fully human antibody specifically selected for its neutralization of tau neuritic dystrophy induced by AD brain-derived oligomers. In a blinded trial in mutant human APP knock-in mice, weekly infusions of B28 for four months markedly reduced both amyloid plaques and Aβ oligomers, attenuated plaque-associated astrocytosis and microgliosis, preserved neurons, and lessened memory decline. Biochemical and histological analyses showed that B28 engaged both plaque-bound and diffusible Aβ, forming immune complexes and depleting free Aβ. In in vitro immunoassays, B28 had significantly higher affinity and captured more Aβ from AD brain extracts than did lecanemab. B28 is a potent, aggregate-preferring Aβ antibody that clears plaques and decreases gliosis, supporting its clinical development.
Trimming of the three glucose residues decorating nascent N-glycoproteins is a critical step for their entry into the endoplasmic reticulum quality control (ERQC) and recognition by ER chaperones. However, the functional...Trimming of the three glucose residues decorating nascent N-glycoproteins is a critical step for their entry into the endoplasmic reticulum quality control (ERQC) and recognition by ER chaperones. However, the functional relevance of the second glucose (G2) and the regulatory step upstream of its removal by glucosidase II (GCS2) remain poorly understood. Here, we report that TUSC3, a component of the oligosaccharyltransferase (OST) complex, regulates G2 to G1 trimming on N-glycosylated bone morphogenetic protein 4 (BMP4) and its Drosophila homolog Dpp to promote their ERQC entry. Loss- and gain-of-function genetic experiments and biochemical assays in mammalian cells and flies indicate that TUSC3 serves as a dosage-sensitive gatekeeper that influences the decision between proper folding and secretion versus elimination by ER-associated degradation for the BMP4 molecules, thereby tuning BMP signaling. Together, these data reveal an unrecognized role for an OST component in early glycoprotein maturation, relevant to a major developmental signaling pathway.
A critical driver of type 2 diabetes is the failure of insulin-secreting β cells due to dysfunction and loss of cell number or identity. The signaling pathways that trigger these events remain unclear. Here, we identify...A critical driver of type 2 diabetes is the failure of insulin-secreting β cells due to dysfunction and loss of cell number or identity. The signaling pathways that trigger these events remain unclear. Here, we identify an epithelial-to-mesenchymal (EMT)-like program that is activated in β cells to promote their loss with type 2 diabetes. This program is initiated in human and mouse β cells by the EMT transcription factor Yap1. While this protein is normally not present in β cells, Yap1 becomes upregulated in response to oxidative stress and impaired mitochondrial function. Chemical inhibition of Yap1 in islets reverses EMT-like activation while its overexpression in cells triggered the appearance of mesenchymal-like vimentin+ cells. Functionally, blocking Yap1 in isolated islets and in mice improves insulin secretion and alleviates diabetes. Taken together, we have identified a novel pathway of β-cell failure during type 2 diabetes, revealing a potential target for future diabetes treatment.
Prevailing views of reward encoding focus on excitatory neurons with GABAergic interneurons relegated to a supporting role, overlooking their potential to independently encode information. Here we simultaneously examine...Prevailing views of reward encoding focus on excitatory neurons with GABAergic interneurons relegated to a supporting role, overlooking their potential to independently encode information. Here we simultaneously examine reward encoding in GABAergic interneurons in medial prefrontal cortex (mPFC) and ventral hippocampus (vHip) in male mice, regions in which glutamatergic neurons integrate outcomes to modulate task engagement. We find a common state-sensitive encoding motif in GABAergic neurons whereby relative suppression of neural activity maps onto outcome history. Decomposing behavior into bouts of exploration and exploitation, we find that exploration gates encoding of outcome history in both mPFC and vHip GABAergic neurons. Globally, interneuron activity in both regions predicted engagement independent of state, but choice prediction was state-dependent and distributed between mPFC and vHip. Overall, these findings indicate that GABAergic neurons also participate in outcome encoding, with behavioral state shaping their role in reward-processing circuits guiding reward-motivated behavior.
Toll-like receptor (TLR) activation elicits an effective innate immune response by inducing the expression of primary and secondary response genes (PRGs and SRGs). Topoisomerase 1 (TOP1) has emerged as a critical regulat...Toll-like receptor (TLR) activation elicits an effective innate immune response by inducing the expression of primary and secondary response genes (PRGs and SRGs). Topoisomerase 1 (TOP1) has emerged as a critical regulator of innate immune responses; however, its mechanism of action remains largely unclear. Here, we demonstrate that the ectopic expression of TOP1 is sufficient to program TLR-response in naive macrophages, and its catalytic activity is essential for inducible gene expression. TOP1 preferentially localizes to super-enhancers, and TLR activation results in the rapid redistribution of TOP1 from resting-state super-enhancers to stimulus-gained super-enhancers, leading to a transcriptional switch. Notably, TOP1 facilitates the recruitment of BRG1 to stimulus-gained super-enhancers. The cooperation between TOP1 and BRG1 enhances the chromatin accessibility at super-enhancers to preferentially regulate the expression of SRGs. These findings establish TOP1 as a transcriptional regulator that links chromatin remodeling at active super-enhancers with inducible gene expression in response to pathogenic stimuli.
The spatial organization and dynamics of the endoplasmic reticulum (ER) govern when and where ER tubules engage with other organelles and the plasma membrane. We previously found that ER tubules are closely associated wi...The spatial organization and dynamics of the endoplasmic reticulum (ER) govern when and where ER tubules engage with other organelles and the plasma membrane. We previously found that ER tubules are closely associated with desmosomes, but the mechanisms of ER recruitment to these adhesive intercellular junctions were unclear. Here, we demonstrate that recruitment of ER tubules to intercellular junctions is dependent upon E-cadherin association with α-catenin. During junction formation, adherens junctions and ER tubules appear nearly simultaneously at nascent cell-cell contacts, followed by desmosome formation. ER recruitment allows the formation of ER-plasma membrane contact sites (ER-PMCSs) and an assembly comprising adherens junctions, ER-PMCS, and desmosomes. Ablating adherens junctions disrupts this tripartite assembly and perturbs global lipid levels. Collectively, our findings identify cadherins as key organizers of ER-PMCS positioning and suggest that the cell-cell adhesion-organelle unit integrates cellular mechanical elements with plasma membrane homeostasis.
Zheng L, Li M, Gu W
… +16 more, Zhao J, Jiang B, Jiang Q, Liu K, Guo Y, Xu R, Liu X, Zhang T, Yang D, Yang S, Liu L, Liu Q, Wang L, Zheng S, Lu F, Chen X
SARS-CoV-2 infection remains a global health threat, yet its pathogenic mechanisms are incompletely understood. Here, we show that viral nucleocapsid protein (NP) is detectable in the serum of patients with SARS-CoV-2 in...SARS-CoV-2 infection remains a global health threat, yet its pathogenic mechanisms are incompletely understood. Here, we show that viral nucleocapsid protein (NP) is detectable in the serum of patients with SARS-CoV-2 infection independently of viral RNA. Using virus-like particle (VLP) systems and in vitro infection models, we demonstrate that NP is secreted in a vesicle-free form via type I unconventional protein secretion (UPS) pathway. This process is regulated by NP phosphorylation and oligomerization, coordinated by viral structural proteins, and dependent on membrane components including heparan sulfate proteoglycans (HSPGs) and phosphatidylinositol 4,5-bisphosphate (PI (4,5) P). Secreted NP is preferentially taken up by granulocytes and induces the release of inflammatory cytokines, including IL-6 and TNF-α. Our findings shed a light on the secretion mechanism of this pro-inflammatory NP, highlighting it as a potential therapeutic target for COVID-related systemic inflammation.
Hypertrophic scarring (HTS) represents a common clinical challenge characterized by excessive fibroblast activation and tissue fibrosis. However, the upstream signals driving pathological fibroblast proliferation remain...Hypertrophic scarring (HTS) represents a common clinical challenge characterized by excessive fibroblast activation and tissue fibrosis. However, the upstream signals driving pathological fibroblast proliferation remain poorly understood. Here, we identify the G protein-coupled receptor MrgprX2 (human)/MrgprB2 (mouse), traditionally restricted to mast cells, as an inducible pro-fibrotic receptor in dermal fibroblasts during HTS progression. MrgprX2 is markedly upregulated in dermal fibroblasts from HTS, and pharmacological inhibition of MrgprX2 significantly reduces fibrosis in humanized skin organoid models. In mouse studies, the endogenous peptide LL37 emerged as an MrgprX2/B2 activator in fibroblasts, triggering calcium influx, transforming growth factor β1 (TGF-β1) secretion, and proliferation. Genetic ablation of MrgprB2 in fibroblasts significantly reduced fibrosis in vivo, establishing the LL37-MrgprX2/B2-TGF-β1 axis as a key mediator of fibroblast activation and fibrotic remodeling. Together, our findings position MrgprX2/B2 as a critical molecular link between tissue injury-associated signals and fibrotic pathology, offering a promising therapeutic target for fibroblast-driven fibrosis in HTS.
Mitochondria are dynamic organelles that continuously remodel their morphology through fusion and fission in response to cellular cues. While this dynamic behavior is essential for diverse cellular functions, how mitocho...Mitochondria are dynamic organelles that continuously remodel their morphology through fusion and fission in response to cellular cues. While this dynamic behavior is essential for diverse cellular functions, how mitochondrial dynamics influence innate immune responses remains incompletely understood. Here, we show that mitochondrial hyperfusion-induced by loss of the fission factor DRP1 or by cellular stress, including cycloheximide or doxorubicin treatment-is associated with activation of a RIG-I-MAVS-dependent innate immune response and BAX-dependent cytosolic release of mitochondrial RNA. Functionally, our data suggest that this pathway contributes to enhanced susceptibility to NK cell-mediated cytotoxicity in vitro and reduced tumor growth in a xenograft model. Collectively, our findings identify mitochondrial hyperfusion-induced mtRNA release as a mechanism that engages innate immune signaling downstream of impaired mitochondrial dynamics.