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Zheng, H.

Publications and source records attributed to Zheng, H..

At least 19 recordsLinked to original sources

Genomic detection of domoic acid biosynthesis uncovers expanded toxigenic diversity across Pseudo-nitzschia diatoms

Domoic acid (DA) production by diatom genus Pseudo-nitzschia causes recurrent harmful algal blooms with major consequences for marine ecosystems, fisheries, and human health. Predicting DA risk remains challenging because toxin production varies across morphologically similar and cryptic lineages. Consequently, morphology or single marker genes often fail to resolve toxigenic potential. Here, we expand genomic resources for Pseudo-nitzschia by generating and compiling high-quality genomes spanning diverse species and biogeographic origins, establishing a genus-wide phylogenomic framework to investigate the distribution and evolution of the DA biosynthesis (dab) gene cluster. Among chemically characterized strains, the dab pathway was detected in species only with confirmed DA production. While the cluster exhibits a conserved core structure, several lineages display signatures of ongoing evolution, including intronization, locus rearrangement, and pseudogenization. One striking example of dab variation occurs in toxigenic P. australis strains, in which its biochemically validated isodomoic acid A synthase-encoding gene dabC is located outside the dab locus. Metatranscriptomic surveys reveal widespread environmental dab expression across size classes and species, implicating taxa not typically associated with environmental DA events, such as P. cf. obtusa and P. cf. plurisecta. To connect dab expression with chemical output, nutrient limitation experiments in the historically inconsistent DA producer P. pseudodelicatissima combined transcriptional profiling and nontargeted metabolomics demonstrating coordinated dab expression across distinct co-expression modules and DA accumulation in response to silicon limitation. Together, these results refine the phylogenetic scope of DA production and provide a genome-resolved basis for improved molecular monitoring of toxigenic diversity.

genetics↗

Astrocytic sEH-EET signaling regulates microglial lysosomal function and suppresses the STING-Type I interferon pathway in Alzheimer's disease

Background: The development of {beta}-amyloid (A{beta}) pathology in Alzheimer's disease (AD) is accompanied by profound changes in astrocytes and microglia and associated neuroinflammation. Soluble epoxide hydrolase (sEH), which degrades anti-inflammatory epoxyeicosatrienoic acids (EETs), is elevated in the AD brain, yet how EETs restrain inflammation remains poorly understood. Methods: We performed single-nucleus RNA sequencing (snRNA-seq) on brains from wild-type, sEH knockout, 5xFAD, and 5xFAD; sEH knockout mice, and used primary mouse microglia and human induced pluripotent stem cell (iPSC)-derived microglia to define the underlying mechanism. To test cell-type-specific contributions, we generated astrocyte- and endothelial-specific she knockout mice and crossed them with 5xFAD mice. Results: Genetic disruption of sEH in 5xFAD mice markedly reduced the abundance of a type I interferon (IFN)-responsive microglial subcluster and lowered phospho-STING (pSTING) levels. In primary microglia, supplementation with 11,12-EET attenuated STING activation and IFN target gene expression; blocking lysosomal acidification abolished this effect and caused pSTING to accumulate, identifying lysosomal degradation as a critical route for terminating STING signaling. 11,12-EET also enhanced microglial lysosomal acidification and A{beta} phagocytosis. Astrocytic, but not endothelial, disruption of sEH recapitulated the reductions in A{beta} pathology and microglial STING activation seen in global sEH-deficient mice, identifying astrocytes as the major cellular source of EETs regulating this pathway. Conclusion: We define an astrocyte-microglia axis in which astrocytic sEH limits EET availability and thereby sustains microglial STING signaling. By promoting lysosomal clearance of pSTING, EETs suppress type I IFN signaling and enhance microglial A{beta} clearance, highlighting sEH inhibition as a therapeutic strategy targeting both neuroinflammation and lysosomal dysfunction in AD.

neuroscience↗

A microbiota-driven neuroepithelial feed-forward circuit drives gastroesophageal junction tumorigenesis

The gastroesophageal junction (GEJ) is continuously exposed to refluxed bile acids and microbial perturbations, yet how these environmental cues are converted into persistent oncogenic signaling is unknown. Here we show that bile acid remodeling enriches the oral commensal Prevotella melaninogenica at the GEJ, where bacterial succinate activates both vagal sensory neurons and SUCNR1-expressing tuft cells. Activated tuft cells release 15-deoxy-12,14-prostaglandin J2 (15-d-PGJ2), which sensitizes sensory neurons and sustains nerve remodeling, while neuronal CGRP drives expansion and tuft-cell differentiation of neuro-responsive epithelial progenitors through RAMP1. This self-reinforcing microbiota-neuron-epithelium circuit promotes dysplastic progression, and its genetic or pharmacological disruption, including with the approved CGRP antagonist rimegepant, suppresses tumor development, revealing an interceptable mechanism linking environmental dysbiosis to cancer initiation through neural circuits.

cancer biology↗

Characterization of Congestive Heart Failure Phenotype in a Murine Model of JAK2V617F-positive Myeloproliferative Neoplasm

Background: Murine models are widely used to investigate cardiovascular disease (CVD), yet many established models rely on invasive surgery or genetic manipulation to induce hyperlipidemia and therefore may not fully capture the gradual cardiovascular consequences of mutant hematopoiesis. Tie2-Cre/-FF1/- (Tie2FF1) mice express JAK2V617F mutation in both hematopoietic and endothelial cells and develop spontaneous CVD on a standard chow diet. Methods: We applied a comprehensive, non-invasive cardiovascular phenotyping protocol to 1-year-old Tie2FF1 mice and age-matched controls. Assessments included transthoracic echocardiography, coronary flow reserve by Doppler ultrasound, quantitative analysis of coronary arteriolar structure and perivascular fibrosis, endocardial histology and subendocardial collagen deposition, and histologic evaluation of pulmonary and hepatic congestion. Results: Tie2FF1 mice demonstrated left ventricular dilation, increased cardiac mass, and mildly reduced systolic function without obstructive epicardial coronary disease. Coronary microvascular remodeling was evident by arteriolar narrowing and increased perivascular fibrosis, while coronary flow reserve was markedly reduced in an exploratory cohort. Endocardial endothelial disruption and increased subendocardial fibrosis were also observed. In addition, Tie2FF1 mice showed increased lung and liver weights, pulmonary fluid accumulation, alveolar septal thickening, pulmonary vascular fibrosis, hepatic sinusoidal dilatation, and centrilobular hepatocyte swelling, providing objective evidence of clinically relevant heart failure. Significance: These findings establish Tie2FF1 mice as a spontaneous, non-invasive model with features of coronary microvascular and endocardial endothelial dysfunction and heart failure with mildly reduced left ventricular ejection fraction. The integrated approach described here provides a practical framework for comprehensive murine cardiovascular phenotyping beyond traditional atherosclerosis- and surgery-based models.

pathology↗

PAXIP1-PAGR1 directs cohesin recruitment during break-induced telomere repair

Cohesin is a conserved multiprotein complex (SMC1, SMC3, RAD21, and either STAG1 or STAG2) that organizes three-dimensional genome architecture and regulates chromosome segregation, gene expression, and DNA damage repair (1-4). Following double-strand breaks (DSBs), cohesin is recruited to sites of DNA damage - a process considered essential for efficient homologous recombination (5-15). Yet how DSB signaling elicits cohesin recruitment and subsequent cohesion establishment remains poorly understood. Here we show that telomere replication stress activates de novo STAG2-cohesin loading, thereby promoting break-induced telomeric DNA repair. We demonstrate that this DNA break-elicited cohesin recruitment is strictly controlled by the BRCT domain-containing DNA damage recognition factor PAXIP1 and its functional partner PAGR1. Cryo-electron microscopy structure reveals that PAGR1, together with PAXIP1, physically binds to a composite interface formed by the STAG2-RAD21 cohesin subcomplex. Complementary mutational and biochemical analyses define the molecular basis of this interaction and establish its essential role in break-induced cohesion establishment. Furthermore, we show that PAXIP1-PAGR1-enacted STAG2-cohesin recruitment complements with the PML body-associated pathway in orchestrating break-induced alternative lengthening of telomeres (ALT). Concurrent depletion of PML together with PAXIP1, PAGR1 or STAG2 disrupts ALT-mediated telomere maintenance, leading to end-to-end chromosomal fusion and mitotic cell death. Collectively, these findings uncover a distinctive molecular mechanism through which DSB signaling directs de novo cohesion establishment, and highlight its critical importance in break-induced telomere repair.

molecular biology↗

Proteomic analysis of Stony Coral Tissue Loss Disease demonstrates coral-algal dysbiosis during disease progression

Stony Coral Tissue Loss Disease (SCTLD) has devastated Caribbean reefs, yet the host molecular response to infection is poorly understood. Previous gene expression studies of diseased corals identified shifts in the immune response, apoptosis, and coral-algal dysbiosis. Here, we characterized the proteomic response of Diploria labyrinthiformis to SCTLD by comparing protein abundance in healthy tissue from uninfected colonies and apparently healthy and neighboring diseased tissue from infected colonies. These results were compared with existing metagenomic data from the same samples that previously demonstrated significant shifts in the coral microbiome due to SCTLD. We identified 480 differentially abundant proteins when comparing diseased lesion and healthy tissues, but only 12 between apparently healthy and healthy tissues. Pathway-level analysis provides evidence of immune suppression in apparently healthy tissue, suggesting that host molecular responses precede visible disease progression. Diseased lesion tissues showed wound-healing responses combined with a decreased abundance of proteins involved in symbiosome maintenance and increased oxidative stress responses, consistent with host-algal dysbiosis. This result correlates with the previous metagenomic analysis of these samples which found that infected colonies exhibit distinct algal symbiont communities dominated by Symbiodinium necroappetens, whereas healthy colonies are dominated by Durusdinium trenchii and Breviolum spp. Comparison with existing transcriptomic studies revealed both shared and distinct molecular responses, underscoring the importance of integrating multi-omics approaches to understand coral diseases. Our results suggest that SCTLD in D. labyrinthiformis is associated with early immune suppression, coral-algal dysbiosis, oxidative stress, and subsequent wound-healing responses.

ecology↗

Backbone Thioamide Substitution Enhances the Activity of Short Peptides in Modulating the Aggregation of α-Synuclein

The non-amyloid-{beta} component (NAC) region of the Parkinson's-associated protein -synuclein plays a key role in its pathogenic aggregation, motivating the development of molecules that target this critical region. Here, we show that a minimal NAC-derived motif, 66VGGAVVT72, can be reprogrammed through backbone engineering to modulate -synuclein aggregation. Backbone thioamide substitution of this peptide enhances its interactions with -synuclein fibrils and accelerates aggregation, whereas N-methylation disrupts {beta}-sheet hydrogen bonding and inhibits fibrillization. Strikingly, combining these modifications yields hybrid peptides that inhibit the fibrillization of full-length -synuclein at sub-stoichiometric concentrations. Consistent with in vitro results, these backbone-modified peptides can also reduce seeded -synuclein aggregation in cells. These results establish that minimal amyloidogenic sequences can be systematically tuned from aggregation promoters to inhibitors through backbone-level perturbations, particularly thioamide incorporation.

biochemistry↗

Multimodal spatial-omics reveal the heterogeneity and intercellular network characteristics of papillary craniopharyngiomas.

Despite significant advancements in microsurgical techniques in recent years, the treatment and prognosis of craniopharyngiomas remain unsatisfactory. As a central nervous system tumor located adjacent to important brain structures such as the hypothalamus-pituitary axis and accompanied by a highly inflammatory microenvironment, the tumor heterogeneity and tumor microenvironment characteristics of papillary craniopharyngiomas (PCPs) remain unclear. In this study, we integrated multimodal single-cell and spatial profiling from PCP tissue and peripheral blood mononuclear cells (PBMCs) to elucidate the tumor heterogeneity and microenvironment characteristics of PCP. Our single-cell and spatial analyses defined four specific tumor cell states in PCP, representing specific transcriptional regulatory programs and spatial heterogeneity characteristics during tumor progression. By constructing a spatial niche composed of tumor, immune, and stromal cells, we analyzed the cellular and spatial ecosystem of PCP at multiple levels to further assess the communication relationships between different tumor cell states and microenvironment cells. This study established a multidimensional molecular atlas of PCP from the perspectives of cell state, spatial structure, and microenvironment interactions, providing a foundation for understanding its biological behavior and exploring new intervention strategies.

cancer biology↗

Life without cytoplasm: sperm sustain protein production utilizing cytoplasmic droplets and mitochondria as translational apparatuses

Sperm present a unique paradox: heavily compacted chromatin silences transcription, and loss of cytoplasm during spermiation eliminates the conventional translational apparatus, yet sperm require [~]10 days of protein-demanding epididymal maturation to acquire motility and fertilization competence. How sperm produce the necessary proteins has remained enigmatic. Here, we show that mammalian sperm sustain protein synthesis through a biphasic translational program. In testicular sperm, a residual cytoplasmic droplet retains the full complement of translational machinery, including ribosomes and intact tRNAs, and supports nascent protein synthesis. As sperm enter the epididymis, this droplet is progressively fragmented, and protein synthesis shifts to the midpiece, where mitochondrial translation machinery becomes active. Proteomic and functional analyses indicate that both systems contribute to sperm maturation. Inhibiting cytoplasmic translation in testicular sperm or mitochondrial translation in epididymal sperm abolishes motility. These findings reveal how cytoplasm-free sperm overcome transcriptional silence to complete maturation and support male fertility. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=137 SRC="FIGDIR/small/744062v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@e4285forg.highwire.dtl.DTLVardef@11685d7org.highwire.dtl.DTLVardef@1ad1913org.highwire.dtl.DTLVardef@1495d6a_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

Paternal Metabolic Reversal Remodels Sperm RNA Profiles and Ameliorates Intergenerational Metabolic Disorder in Mice

Paternal obesity increases metabolic risk in offspring, but whether this risk can be reduced by restoring paternal health before conception remains unresolved. We developed a within-sire induction-and-reversal model in outbred CD1 mice in which high-fat diet (HFD)-exposed males generated offspring before and after transition to an ingredient-matched control diet with voluntary exercise. HFD caused obesity, glucose intolerance, insulin resistance, and extensive remodeling of sperm mRNA, lncRNA, and sncRNA profiles, together with transcriptomic changes in metabolic tissues. Diet and exercise reversal normalized paternal metabolic indices and broadly restored tissue RNA profiles, although sperm retained a limited transcriptional memory of prior HFD exposure. Offspring sired before reversal developed sex-dependent metabolic dysfunction despite control-diet rearing, whereas offspring sired after reversal showed substantial improvement. These findings show that paternal metabolic risk is modifiable before conception and that this reversibility is linked to remodeling of sperm RNA. (140 words) HighlightsO_LIPaternal HFD-Ex induces obesity, glucose intolerance and insulin resistance in CD1 males C_LIO_LISperm shows much stronger RNA response than four metabolic organs profiled C_LIO_LIDiet and exercise reversal restores metabolism and RNA profiles in sperm and four metabolic organs analyzed C_LIO_LIOffspring metabolic risk is reduced when sires conceive after reversal through diet and exercise intervention C_LI eTOC BlurbChen, Magalhaes, et al. show that paternal metabolic recovery before conception remodels sperm RNA and reduces transmission of HFD-associated metabolic risk to offspring in a within-sire mouse model.

genetics↗

Ribonucleotide Reductase Inhibition Overcomes FLT3 Inhibitor Resistance in Acute Myeloid Leukemia

Internal tandem duplication mutations in FLT3 (FLT3ITD) occur in approximately 30% of patients with acute myeloid leukemia (AML) and are among the most common genetic alterations in this disease. FLT3ITD is a major driver of AML and is associated with poor clinical outcomes. Although FLT3 inhibitors (FLT3is) have significantly improved outcomes for patients with FLT3ITD+ AML, acquired resistance remains a major barrier to durable clinical benefit. Reactivation of RAS/MAPK signaling, often driven by activating NRAS mutations, is a major mechanism of FLT3i resistance in AML; however, effective strategies to overcome this resistance remain lacking. Here, we identify ribonucleotide reductase (RNR) as a critical therapeutic vulnerability in NRAS-driven FLT3i-resistant FLT3ITD+ AML. Activation of RAS signaling through SPRY3 loss or oncogenic NRAS mutations confers robust resistance to FLT3is, whereas pharmacologic inhibition of RNR with multiple inhibitors, as well as siRNA-mediated RNR suppression, reverses FLT3i resistance and restores FLT3i sensitivity across multiple FLT3ITD+ AML models in vitro. In vivo, clofarabine, an FDA-approved RNR inhibitor (RNRi), significantly overcomes NRAS mutation-driven FLT3i resistance. In combination with FLT3 inhibition, clofarabine markedly suppresses the progression of FLT3i-resistant AML and significantly prolongs survival in cell line-derived xenograft (CDX) models. Importantly, the therapeutic efficacy of the gilteritinib/clofarabine combination was independently validated in two genetically distinct patient-derived xenograft (PDX) models harboring different NRAS mutations, demonstrating robust reduction of leukemia burden and confirming the generalizability of RNR inhibition in primary FLT3i-resistant AML. Together, these findings identify a previously unrecognized therapeutic vulnerability in FLT3i-resistant FLT3mut+ AML and establish RNR inhibition as an effective strategy to overcome FLT3i resistance, providing a strong rationale for the clinical evaluation of RNRis in combination with FLT3is in patients with resistant AML. SignificanceAlthough FLT3 inhibitors (FLT3i) are an important therapeutic advance in FLT3ITD+ AML, resistance commonly develops. We identified ribonucleotide reductase (RNR) as a new key vulnerability in NRAS-driven FLT3i-resistant AML and demonstrated that multiple RNRis, including the FDA-approved agent clofarabine, restore FLT3i sensitivity and enhance antileukemic activity, supporting a clinically actionable combination strategy.

cancer biology↗

Cell Penetrating Thyclotides Facilitate Efficient Delivery of Bioactive Peptides into Cells

Cell penetrating thyclotides (CPTs) are synthetic molecules that promote highly efficient cellular uptake and endosomal escape of bioactive peptides. While peptides are valuable as medicinal agents, their translation to therapies is often limited by their inability to cross cell membranes. CPTs have a unique combination of chiral tetrahydrofurans and polar sidechains within a molecular scaffold that can be optimized to efficiently deliver peptide cargo into cells. The cellular uptake and endosomal escape of two peptides with anticancer biological activities but low bioavailabilities were remarkably improved after conjugation to a CPT. Using CPTs to overcome barriers to cellular uptake represents a new direction for the intracellular delivery of bioactive molecules, and will accelerate drug development for new medical therapies.

biochemistry↗

Sensory neurons encode long-term inflammatory memory that promotes gastric regeneration and tumorigenesis

Inflammatory memory has emerged as a fundamental principle by which prior injury shapes future tissue responses, yet whether sensory neurons participate in long-term tissue memory remains unknown. Here, we show that vagal sensory neurons acquire a durable, experience-dependent state following gastric injury or Helicobacter pylori infection, leading to enhanced regeneration, metaplasia, and tumor progression upon re-injury. This neuronal program is stable, functionally transferable, and sufficient to drive epithelial responses in vivo. Mechanistically, injury-activated ILC2s establish sensory neuronal memory through IL-13-dependent epigenetic remodeling, inducing SMYD4-mediated H3K4 trimethylation and promoting CGRP-dependent activation of gastric epithelial cells. Together, our findings support a model in which tissue memory is not restricted to epithelial or immune compartments but emerges through coordinated long-term adaptations across multiple cellular systems. Within this framework, sensory neurons provide a persistent substrate for recall responses, linking prior inflammatory experience to sustained epithelial plasticity and cancer susceptibility. HIGHLIGHTSO_LISensory neurons function as a durable compartment of tissue memory. C_LIO_LICGRP-RAMP1 signaling couples neuronal memory to gastric stem cells. C_LIO_LIILC2-derived IL-13 establishes sensory neuronal memory programs. C_LIO_LISMYD4-mediated H3K4me3 stabilizes long-term neuronal memory. C_LIO_LINeuronal memory promotes gastric regeneration and tumor susceptibility. C_LI

cancer biology↗

Ventricular Expansion Couples Hyperosmotic Stress to Thirst

Thirst is thought to arise from osmotic signals detected by circumventricular organs, yet how hyperosmotic stress activates mechanosensitive channels remains unclear because cell shrinkage should reduce membrane tension. Here we identify a brain-scale mechanical signal that couples systemic osmotic stress to drinking. In mice, hypertonic saline rapidly increased serum and cerebrospinal fluid osmolality, expanded the lateral ventricles, and promoted water intake. Relieving or blocking ventricular deformation attenuated drinking without eliminating osmotic gradients. Hyperosmotic challenge also produced localized deformation of periventricular cells, where spatial transcriptomics revealed candidate mechanosensitive channels, including Tmem63b and Piezo1. Thus, ventricular expansion provides a mechanical component of osmotic thirst, uncovering an osmo-mechanical layer of interoceptive regulation.

neuroscience↗

A biointegrated living brain stimulator evokes specific neural signalling

Implanted brain stimulators play a crucial role in treating various neurological disorders, including Parkinsons disease (PD), Alzheimers disease, epilepsy, and depression. However, none of the existing implanted brain stimulators can realize specific neuromodulation due to fundamental disparities in signal transmission between electrical signal-induced neuronal responses and neurotransmitter-evoked neural signalling in natural neural circuits, leading to persistent challenges in biosafety and therapeutic effectiveness. Inspired by the dopaminergic neural circuit, we report a biointegrated living brain stimulator (BBS) that integrates ferroelectric bioelectronics, dopaminergic cells, and a gelatin hydrogel matrix, enabling dopamine neurotransmitter-evoked neural signalling. In contrast to conventional brain stimulators, the BBS are capable of programmed secretion of physiological-level dopamine, specifically activating nigral dopamine pathways and restoring motor function in a rodent PD model. By integrating the advantages of both bioelectronics and medicine, this lifelike BBS offers a great promise for next-generation bioelectronics, medicine, and brain-machine interfaces.

bioengineering↗

Oncofetal RNA-binding proteins of IGF2BP family suppress IRF-3 and NF-kB dependent transcription downstream of cytosolic RNA sensors

Activation of innate inflammatory signaling and tumor-specific antigen presentation in cancer cells provides a foundation for anti-cancer immunotherapies. Here, we show that the insulin-like growth factor 2 mRNA-binding proteins (IGF2BP1, IGF2BP2, and IGF2BP3), which are upregulated across diverse human malignancies, including acute myeloid leukemia (AML), suppress RNA-sensing pattern recognition receptor signaling and downstream ISRE-and NF-{kappa}B-dependent transcription. Among these pathways, RIG-I signaling is particularly sensitive to IGF2BP-mediated inhibition. This suppressive effect is strongest when all three IGF2BP paralogs are co-expressed, especially in embryonic-like hematoendothelial cells and leukemia stem cells. Mechanistically, IGF2BPs suppress innate immune signaling by directly binding to TNFAIP3 mRNA and promoting its expression. Consequently, inhibition of IGF2BPs activates innate immune signaling and induces MHC class I gene expression in AML cells, highlighting IGF2BPs as promising therapeutic targets to enhance RIG-I- and TLR-based cancer immunotherapies. HighlightsO_LIIGF2BP family of proteins regulate PRR responses C_LIO_LIIGF2BP levels affect chromatin accessibility and pan-transcriptome C_LIO_LISV40 large T antigen induces de novo expression of IGF2BPs C_LIO_LITNFAIP3 mRNA levels and stability are regulated by IGF2BPs C_LI

cancer biology↗

A Lineage-Specific Peptide Suppresses Juvenile Hormone to Drive Reproductive and Longevity Reprogramming in Ants

In ants and other eusocial insects, reproductive division of labor is tightly regulated by juvenile hormone (JH), which suppresses reproduction in most individuals to maintain the worker caste. However, how social cues trigger systemic JH suppression to permit reproductive activation remains unclear. In the ant Harpegnathos saltator, workers respond to queen loss by engaging in sustained ritualistic dueling and transitioning into reproductive, long-lived pseudoqueens (gamergates). This provides a powerful model for investigating the molecular basis of socially induced plasticity. We examined the hemolymph proteome of transitioning ants and identified HCRG1, a lineage-restricted peptide upregulated during dueling, as a circulating factor that physically interacts with Hex70c, a broadly conserved JH-binding Hexamerin. HCRG1 promotes ovarian development by antagonizing JH signaling. Expression of ant HCRG1 in the heterologous solitary model Drosophila also extends lifespan. These findings identify an evolutionarily derived circulating factor that links social sensory perception to systemic JH suppression, enabling coordinated reproductive and longevity transitions in a social insect.

evolutionary biology↗

The Par complex regulates apical-basal cell polarity through modulation of FAK signaling homeostasis

Cell polarity complexes are essential for embryogenesis, but their regulatory mechanisms during early developmental transitions remain incompletely understood. Here, we individually deleted the Crumbs, Par, and Scrib polarity complexes in mouse embryonic stem cells (mESCs). While loss of any single complex did not affect pluripotency or proliferation, deletion of Par complex disrupted the naive-to-primed transition and impaired subsequent differentiation, particularly lumen formation in neural tube organoids. Mechanistically, Par complex deficiency led to hyperphosphorylation of focal adhesion kinase (FAK) at the primed stage, driving a morphological shift from flat monolayer clusters to dome-shaped colonies. FAK inhibition rescued the aberrant morphology. Upstream, Par complex loss increased AKT phosphorylation, which remodeled extracellular matrix (ECM) and regulated integrin signaling via FURIN-LEFTY, ultimately modulating FAK activity. In addition, conditioned medium from wild-type cells partially rescued differentiation defects in Par knockout cells in a LEFTY-dependent manner. These phenotypes were consistently observed in naive-to-primed transition, neural stem cell differentiation, embryoid body formation, teratoma assays, and neural tube organoid differentiation. Together, these findings establish a Par complex-AKT-FURIN-LEFTY-ECM-integrin-FAK signaling cascade that links apical-basal polarity to early lineage specification and morphogenesis, providing a mechanistic framework for how polarity cues are translated into developmental outcomes. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/722465v1_ufig1.gif" ALT="Figure 1"> View larger version (64K): org.highwire.dtl.DTLVardef@179e0adorg.highwire.dtl.DTLVardef@8d83bdorg.highwire.dtl.DTLVardef@c425fforg.highwire.dtl.DTLVardef@19a8ee5_HPS_FORMAT_FIGEXP M_FIG C_FIG Significance StatementThis study elucidates the molecular mechanism by which the Par complex regulates the establishment of cell polarity. The authors demonstrate that the Par complex promotes the expression of the protein convertase FURIN via AKT signaling, thereby enhancing the maturation and secretion of LEFTY protein. This process remodels the ECM and modulates integrin signaling, ultimately regulating FAK activity and controlling the establishment of cell polarity. These findings reveal how polarity cues govern early lineage specification and morphogenesis, with implications across multiple developmental contexts.

developmental biology↗