Biology subjects

Zhang, P.

Publications and source records attributed to Zhang, P..

At least 91 records · Page 5Linked to original sources

bioRxiv2025

Dynamic Meta-Networking Identifies Distinct Network Correlates of Positive and Negative Formal Thought Disorder in Schizophrenia

Formal thought disorder (FTD) is a core symptom of schizophrenia, yet the neural network mechanisms underlying this phenotype remain poorly understood. In this study, we applied a dynamic meta-networking framework, which captures temporally recurring functional network states, to investigate alterations in the language and executive control networks and their associations with positive and negative FTD. Resting-state fMRI data were collected from three independent cohorts: a discovery cohort comprising 150 first-episode, drug-naive patients with schizophrenia and 175 healthy controls (HCs); a replication cohort including 183 first-episode, drug-naive patients and 109 HCs; and a third cohort consisting of 71 patients who had received two weeks of antipsychotic treatment and 71 HCs. Meta-networking analysis identified four distinct resting-state meta-states within both the language and executive control networks. Connectivity-behavior correlation analyses and machine-learning regression models revealed that positive FTD was associated with aberrant connectivity across specific meta-states in both networks. In contrast, negative FTD was linked exclusively to dysfunction within two meta-states of the executive control network. Notably, these polarity-specific, multi-state connectivity disruptions normalized following short-term antipsychotic treatment, highlighting their potential as clinically relevant neuroimaging biomarkers.

neuroscience↗

bioRxiv2025

Enterococcus faecalis delivers Obg GTPase via extracellular vesicles to instigate mTOR activity and promote HCC tumorigenesis

Hepatocellular carcinoma (HCC) is a malignant tumor that has been associated with dysbiosis of the gut microbiota. However, how the gut microbiota plays an oncogenic role in HCC remains largely unknown. Here, we show that Enterococcus faecalis (E. faecalis) is highly enriched in liver tumor tissues and is positively correlated with pathogenesis of HCC. E. faecalis promotes liver cancer cell proliferation, protein translation, cell migration and tumorigenesis. Mechanistically, we found that EF-derived extracellular vesicles (EF-EVs) deliver EF-Obg GTPase to activate host mTOR, thereby promoting liver cancer progression. Intriguingly, the EF-Obg protein exerts its influence on the mTOR pathway via a Ras-like G domain involved in GTP binding. EF-Obg exhibits a striking homology with the G1 site of the G domain of Rheb, a key positive regulator of mTOR. Obg gene is critical for E. faecalis to activate mTOR to promote hepatocarcinogenesis based on an engineered obg knockdown strain by CRISPR interference experiment. Clinically, abundant EF-Obg protein expression is correlated with enhanced activation of mTOR, leading to poor overall survival in HCC patients. Significantly, treatment of mTOR inhibitor Everolimus confers effectiveness in EF-colonized liver cancer orthotopic model, suggesting that Everolimus therapeutic approach can be effective for liver cancer patients with enriched E. faecalis. Taken together, we provide mechanistic and functional evidence to verify a direct causal relationship between tumor-resident E. faecalis enrichment and liver carcinogenesis, revealing that EF-Obg functions as a previously unidentified cross-kingdom activator of mTOR to promote liver tumorigenesis.

cell biology↗

bioRxiv2025

Lifespan Trajectories of Asymmetry in White Matter Tracts

Asymmetry in white matter is believed to give rise to the brains capacity for specialized processing and is involved in the lateralization of various cognitive processes, such as language and visuo-spatial reasoning. Although studies of white matter asymmetry have been previously documented, they have often been constrained by limited age ranges, sample sizes, or the scope of the tracts and structural features examined. While normative lifespan charts for brain structures are emerging, comprehensive charts detailing white matter asymmetries across numerous pathways and diverse structural measures have been notably absent. This study addresses this gap by leveraging a large-scale dataset of 35,120 typically developing and aging individuals, ranging from 0 to 100 years of age, from 50 primary neuroimaging studies. We generated comprehensive lifespan trajectories for 30 lateralized association and projection white matter tracts, examining 6 distinct microstructural and macrostructural features of these pathways. Our findings reveal that: (1) asymmetries are widespread across the brains white matter and are present in all 30 pathways; (2) for a given pathway, the degree and direction of asymmetry differ between features of tissue microstructure and pathway macrostructure; (3) asymmetries vary across and within pathway types (association and projection tracts); and (4) these asymmetries are not static, following unique trajectories across the lifespan, with distinct changes during development, and a general trend of becoming more asymmetric with increasing age (particularly in later adulthood) across pathways. This study represents the most extensive characterization of white matter asymmetry across the lifespan to date, charting how lateralization patterns emerge, mature, and change throughout life. It provides a foundational resource for understanding the principles of white matter organization from early to late life, its relation to functional specialization and inter-individual variability, and offers a key reference for interpreting deviations during healthy development and aging as well as those associated with clinical populations.

neuroscience↗

bioRxiv2025

Programmable Aptamer-Embedded Circular RNAs for Targeted Antigen-Presenting Cells Immunotherapy

The targeted delivery of mRNA to specific cell types in vivo remains a major unmet need in mRNA-based therapeutics. Conventional strategies rely on nanocarriers engineered with various modifications. However, these exogenous materials could cause adverse reactions, and their complex manufacturing processes often hinder clinical application. By leveraging the innate programmability of RNA sequences, we herein report a carrier-free, scalable, and programmable aptamer-embedded circular RNAs (Apt-circRNAs) design that confers targeting capability through the strategic incorporation of different aptamers at varying densities, while retaining circular RNA stability and protein production capability. Experimental results show that antigen-loaded Apt-circRNAs enable targeted delivery to antigen-presenting cells (APCs), drive endogenous antigen expression, activate antigen-specific T cells, and elicit potent immune responses that mediate clearance of both early-and late-stage tumors in mouse models. In humanized models of colorectal cancer, the combination of Apt-circRNA and PD-1 blockade produced synergistic antitumor effects and significantly reshaped the tumor microenvironment. In a first-in-human (FIH) clinical trial, Apt-circRNA vaccine encoding KRAS G12D/G12V neoantigens exhibited a favorable safety profile and induced robust immune activation, T cell mobilization, and neoantigen-specific immune responses. With this study, we have established a new paradigm in carrier-free, APC-targeted RNA vaccine design, offering a safe and effective platform for next-generation cancer immunotherapy.

bioengineering↗

bioRxiv2025

RNAcentral in 2026: Genes and literature integration

RNAcentral was founded in 2014 to serve as a comprehensive database of non-coding RNA sequences. It began by providing a single unified interface to more specialised resources, and now contains 45 million sequences. It has grown beyond providing a single interface to many specialised resources and now provides several services and analyses. These include secondary structure prediction with R2DT, sequence search, and analysis with Rfam. Since its last publication in 2021, RNAcentral has developed two major features. First, literature integration with the development of LitScan and LitSumm. LitScan automatically identifies and links relevant publications to RNA entries, while LitSumm uses natural language processing to generate functional summaries from the literature. Together, these tools address the critical challenge of connecting sequence data with scattered functional knowledge across thousands of publications. Secondly, RNAcentral has created gene level entries. Gene level entries represent a large structural change to RNAcentral. While RNAcentral previously organized data exclusively at the sequence level, we now group related transcripts into gene-centric views. This allows researchers to explore all isoforms, splice variants, and related sequences for a gene in a unified interface, better reflecting biological organization and facilitating comparative analyses. RNAcentral is freely available at: https://rnacentral.org.

bioinformatics↗

bioRxiv2025

Genome structural plasticity and copy number dynamics shape adaptive evolution in a barley fungal pathogen

Leaf rust, caused by Puccinia hordei, is one of the most important diseases of barley globally. Here, we report the first haplotype-resolved chromosome-level genome assembly for P. hordei. To gain deeper insight and understanding of the P. hordei genome, we generated such assemblies for two Australian isolates with contrasting virulence, one collected in the 1970s and one in 2001. The two haplotype-phased and chromosome-level assemblies were used to investigate genome architecture in P. hordei and to investigate variability and evolutionary relationships of 41 virulence-divergent isolates that were collected over a 54-year period (1966-2020) in Australia. We report, for the first time in a rust fungus, evidence of a conserved chromosome, chromosome 9, which is enriched for structural variation and accessory features that imply it functions as a compartmentalized core chromosome with regions subject to rapid diversification, potentially acting as a structural hotspot in adaptive evolution in P. hordei. Clear genetic stratification into clonal and recombining lineages was uncovered, with evidence of both long-term asexual propagation and recombination. Analyses of haplotype-resolved mating-type gene phylogenies and chromosome 9 k-mer profiles confirm divergence at key loci underpinning reproductive modes, distinguishing clonally derived from sexually recombined groups. We also identified pervasive copy number variation across the P. hordei genomes, with clonal lineage-specific duplications. Consistent with this finding, the study for the first time links copy number variation of the Cyp51 gene to fungicide insensitivity. This latter discovery is highly significant as it represents the first documented case of fungicide insensitivity in a rust pathogen in which an underlying genetic mechanism has been identified. Together, these findings illuminate how genome structure, recombination, and structural variation shape the evolution and adaptation of P. hordei, providing a guidance for future surveillance and management of this pathogen.

genomics↗

bioRxiv2025

Patterns of Mitochondrial ATP Predict Tissue Folding

The construction of complex tissue shapes during embryonic development results from spatial patterns of gene expression and mechanical forces fueled by chemical energy from ATP hydrolysis. We find that chemical energy is similarly patterned during morphogenesis. Specifically, mitochondria are locally enriched at the apical sides of epithelial cells during apical constriction, which is widely used across the animal kingdom to fold epithelial tissues. Timelapse imaging, spatial transcriptomics, and measurements of oxygen consumption rate reveal that mitochondrial density, potential, and ATP increase in epithelial cells prior to actomyosin contraction and tissue folding, which is prevented by inhibiting oxidative phosphorylation. Mitochondrial enrichment and apicobasal patterning are conserved during apical constriction in flies, chicks, and mice, and these subcellular patterns can be used to predict computationally patterns of tissue folding. These findings highlight a spatial dimension of bioenergetics in embryonic development.

developmental biology↗

bioRxiv2025

C9orf72/SMCR8 complex maintains microglial homeostasis via RAB8A-ESCRT-mediated lysosomal repair

Microglia are critical regulators of neuroinflammation and neurodegeneration. Haploinsufficiency of C9orf72, the most common genetic cause of ALS and FTD, has been mainly linked to autophagy-lysosomal pathway defects, but its precise role in microglial lysosomal function remains unclear. Here we identify the C9orf72/SMCR8 complex as a key regulator of microglial homeostasis through lysosomal repair. Loss of C9orf72 and SMCR8 in mice causes age-dependent neuroinflammation and microgliosis, with microglia adopting a disease-associated state. In aged CNS tissue, microglia display lysosomal damage, marked by galectin-3 upregulation and its accumulation on lysosomes. To model this process, we applied the lysosomotropic agent LLOMe to microglia, which recapitulated lysosomal damage and revealed defective recruitment of phosphorylated RAB8A and the ESCRT machinery in C9orf72/SMCR8-deficient cells. Notably, mutant microglia accumulate GTP-bound RAB8A, which becomes aberrantly hyperphosphorylated and mislocalized to non-lysosomal vesicles. We further show that the GAP activity of the C9orf72/SMCR8 complex is essential for lysosomal repair. These findings uncover a previously unrecognized role for the C9orf72/SMCR8 complex in coordinating RAB8A-ESCRT-mediated lysosomal repair, thereby safeguarding microglial homeostasis and limiting neuroinflammation.

cell biology↗

bioRxiv2025

From recall to reset: the role of DNA (de)methylation in modulating plant immune memory

Immune memory enables plants to respond more effectively to recurrent pathogen infections. Epigenetic changes in DNA methylation and small RNAs have been implicated, yet how their temporal dynamics govern the establishment and erasure of immune memory remains unclear. Using a chemically inducible system in Arabidopsis to activate the DNA demethylase REPRESSOR OF SILENCING 1 (ROS1), we establish immune memory against biotrophic pathogens that persists for up to two weeks. Memory establishment coincides with reduced small RNA accumulation and DNA methylation along chromosome arms, revealing gene targets involved in salicylic acid-dependent immunity and DNA damage repair. These changes are progressively reversed during immune memory erasure. In contrast, transposon-rich pericentromeres retain elevated small RNA and DNA methylation levels, consistent with a CLASSY3-associated redistribution of RNA-directed DNA methylation. Our findings show that transient ROS1 activity drives contrasting epigenetic responses across chromosomal regions, shaping both the establishment and erasure of plant immune memory.

plant biology↗

bioRxiv2025

UHRF1 restricts HCoV-229E infection through epigenetic silencing of the viral receptor APN

The emergence of SARS-CoV-2 has posed significant threats to global health, particularly for the older population. Similarly, common human coronaviruses, such as HCoV-229E, which typically cause mild cold-like symptoms, have also been linked to severe diseases, underscoring the need to understand virus-host interactions and identify host factors contributing to viral pathogenesis and disease progression. In this study, we performed a genome-wide CRISPR knockout screen using HCoV-229E and identified Ubiquitin-like with PHD and RING finger domain 1 (UHRF1) as a potent restriction factor. Mechanistically, UHRF1 suppressed HCoV-229E infection by downregulating the expression of its cell entry receptor, aminopeptidase N (APN), through promoter hypermethylation. Focused CRISPR activation screens of UHRF1-downregulated genes confirmed the critical role of APN in HCoV-229E infection and identified additional genes (e.g., SIGLEC1, PLAC8, and heparan sulfate biosynthesis genes) contributing to the restrictive functions of UHRF1. Transcriptomic and single-cell RNA sequencing analysis revealed that UHRF1 expression decreases with age, negatively correlating with increased APN expression. This age-related decline in UHRF1 was further validated in primary alveolar macrophages isolated from elderly individuals, which exhibited heightened susceptibility to HCoV-229E infection compared to those from younger individuals. Our findings highlight UHRF1 as a key age-related host defense factor against coronavirus infection and provide novel insights into the epigenetic regulation of viral entry receptors.

microbiology↗

bioRxiv2025

An In Vitro BRAF Activation Assay Elucidates Molecular Mechanisms Driving the Disassembly of the Autoinhibited BRAF State

The RAF kinases (ARAF, BRAF and CRAF) are essential components of the RAS-ERK signaling pathway, which controls vital cellular processes and is frequently dysregulated in human disease. Notably, mutations that alter BRAF function are prominent drivers of human cancer and certain RASopathy disorders, making BRAF an important target for therapeutic intervention. Despite extensive research, several aspects of BRAF regulation remain unclear. In this study, we developed an in vitro BRAF activation assay using purified autoinhibited BRAF:14-3-32:MEK complexes. Our results show that fully processed, active-state KRAS alone can promote dimer-dependent BRAF activation. Moreover, we found that phosphatidylserine (PS)-containing liposomes synergized with KRAS to promote BRAF activation, achieving activity levels comparable to those observed with BRAF proteins that constitutively dimerize. In contrast, the SMP phosphatase complex had only a minimal effect on BRAF catalytic activity in this system but mediated the dephosphorylation of the negative regulatory pS365 14-3-3 binding site in a manner that was accelerated by the presence of KRAS alone or KRAS and 30% PS liposomes. Finally, we show that inhibitors blocking the BRAF RBD:KRAS interaction were able to suppress the in vitro activation of BRAF, underscoring the critical role of RAS binding in initiating the disassembly of the BRAF autoinhibited state. Thus, this assay provides valuable insights into the steps required for BRAF activation and can serve as an effective screening tool for identifying compounds that may inhibit this process and have therapeutic potential. Significance StatementBRAF is a central intermediate in RAS pathway signaling, and its activity is often elevated in human cancers and RASopathy disorders. Due to the complexity of BRAF activation, identifying compounds that sustainably inhibit BRAF function has proven difficult, emphasizing the need for a more comprehensive understanding of BRAF regulation. Here, we have developed an in vitro BRAF activation assay that elucidates key steps in this process. Our findings demonstrate that RAS binding not only recruits BRAF to the plasma membrane but initiates the disassembly of the autoinhibited monomer, which in the context of the membrane, facilitates BRAF dimerization and activation. This assay advances our understanding of BRAF regulation and provides a novel platform for drug discovery efforts targeting BRAF.

biochemistry↗

bioRxiv2025

Structural assembly of maize CRY-GL2 photosignaling complex provides insights into its regulatory role in cuticular wax biosynthesis

Cryptochromes (CRYs) are blue-light photoreceptors in plants that regulate diverse physiological processes through oligomerization-dependent interactions with downstream effectors. While numerous light-inducible CRY-binding proteins have been identified, the structural basis for photoactivated CRY-effector assembly remains poorly understood. Here we report the crystal structure of a constitutively active maize CRY1c photolyase homology region (ZmCRY1c-PHRW368A) in complex with ZmGL2, a BAHD ptotein directing very-long-chain fatty acid (VLCFA) elongation for cuticular wax biosynthesis. Structural analysis reveals that light-activated ZmCRY1c forms a homotetrameric scaffold generating four symmetric binding sites at subunit interfaces. Each ZmCRY1c protomer engages one ZmGL2 molecule through conformational reorganization of its 16-17 loop and 17 helix, establishing a 4:4 hetero-octameric photosignaling complex validated by mutational profiling and optical design. Remarkably, structural alignment with the ZmCER6-ZmGL2 complex reveals substantial overlap (78%) in ZmGL2 binding interfaces. Biochemical quantification demonstrates that ZmCRY1c suppresses ZmCER6-GL2 enzyme activity in a dose dependent manner, unveiling a light-dependent regulatory switch controlling VLCFA elongation efficiency, though in vivo physiological investigation is awaited. Collectively, our work not only establishes the atomic model of light-activated plant CRY-effector assembly, but also uncovers a previously unrecognized spatial competition between photoreceptor and metabolic enzyme complexes that might function as a photoregulatory paradigm in cuticular wax biosynthesis.

plant biology↗

bioRxiv2025

ZmCRY1s interact with GL2 in a blue light dependent manner to regulate epidermal wax composition in Zea mays

Cryptochromes (CRYs) are photolyase-like blue-light / ultraviolet-A (UV-A) receptors that regulate diverse aspects of plant growth. Maize (Zea mays), a major crop often grown under high UV-B radiation, possesses four copies of CRY. However, it remains unclear whether the multiple copies of CRY in maize have evolved to improve UV tolerance or to acquire new functions. In this study, CRISPR-Cas9-engineered Zmcry mutants were used to investigate the functions of four cryptochromes (ZmCRYs) in maize. The findings revealed that ZmCRYs play a redundant role in mediating blue light signaling and in inhibiting the elongation of the mesocotyl. The results also demonstrated that ZmCRYs mediated blue light-enhanced UV-B stress tolerance in Zea mays by upregulating the expression of genes involved in UV-B stress tolerance-related metabolites such as phenylpropanoid, flavonoid, and fatty acid biosynthesis. Furthermore, blue light was found to influence both the accumulation and composition of epidermal waxes, suggesting that blue light enhances epidermal wax accumulation for UV-B stress tolerance. Additionally, it was discovered that ZmCRY1 directly interacted with GLOSSY2 (GL2) in a blue light dependent manner to mediate blue light promoted C32 aldehyde accumulation, shedding new light on the enigma of aldehyde-forming. These results highlight the critical roles of ZmCRY1s in mediating blue light regulated epidermal wax biosynthesis and UV-B tolerance in Zea mays.

plant biology↗

bioRxiv2025

The Rab5 effector Rabankyrin-5 mediates endosomal fusion and trafficking of Human Papillomavirus during early entry

The fusion of newly formed early endosomal vesicles after endocytosis is a crucial step in viral infection. It facilitates the transition of many viruses from viral internalization to downstream intracellular trafficking within the endosomal network, ultimately enabling their delivery to intracellular replication sites. Despite its significance, the molecular mechanisms regulating the fusion of these vesicles remain poorly understood. In this study, we show that Rabankyrin-5, a Rab5 effector, is essential for the fusion of human papillomavirus (HPV)-containing early endosomes during viral entry. Additionally, Rabankyrin-5 acts as a dynein adaptor, directly binding both the HPV minor capsid protein L2 and the dynein motor complex to link virus-carrying early endosomes to the dynein transport machinery, thereby promoting virus movement along microtubules. These dual functions enable the coordinated integration of endosomal fusion with microtubule-based transport during the early stages of viral entry.

microbiology↗

bioRxiv2025

Chromosomes remain individualized through interphase in embryos of the tardigrade Hypsibius exemplaris

Tardigrades are microscopic animals that can survive exceptional levels of ionizing radiation or desiccation - DNA-damaging conditions that would kill most animals. Irradiation or radiomimetic drug treatment of the tardigrade Hypsibius exemplaris can induce remarkably high expression levels of DNA repair genes, primarily those in the base excision repair and nonhomologous end joining pathways. How tardigrades can repair widespread DNA damage without producing frequent, large-scale chromosome structural abnormalities, like chromosome translocations and fusions, is unknown. Here, we report the results of examining chromosome and nuclear architecture throughout the cell cycle in early embryos of H. exemplaris. We found that H. exemplaris chromosomes are maintained in an individualized form throughout the cell cycle. We were surprised to also find that each chromosome is housed in a fully or partially separate lamin-lined compartment, instead of all chromosomes being housed in a single, nearly spherical nuclear lamina and envelope. Our results reveal unusual chromosomal and nuclear organization in a tardigrade. We speculate that these unexpected features might limit chromosomal rearrangements during DNA damage repair in extreme conditions. SIGNIFICANCE STATEMENTO_LIWe have investigated unusual chromosome organization in an organism that survives extremely DNA-damaging environments, a tardigrade, through early embryonic cell cycles. C_LIO_LIChromosomes in fixed and stained embryos appeared more condensed through interphase than is typical for animal cells. C_LIO_LIChromosomes remained individualized, in fully or partially separate lamin-lined compartments, through interphase. C_LIO_LIThe results reveal a unique nuclear and chromosomal organization in tardigrades, which we speculate might contribute to limiting chromosomal structure abnormalities under DNA damaging conditions in nature. C_LI

cell biology↗

bioRxiv2025

Palmitoylation-dependent activation of NADK promotes NADP+ synthesis and tumorigenesis

NAD kinase (NADK) is the sole cytosolic enzyme that catalyzes the synthesis of nicotinamide adenine dinucleotide phosphate (NADP+) from NAD+. NADP+ is essential for anabolic reactions and redox balance. Here, we show that palmitate facilitates NADP+ synthesis by enhancing NADK palmitoylation and activity. NADK is post-translationally S-palmitoylated on three cysteine residues (Cys22, Cys23, and Cys26) within the amino-terminal domain by the protein-acyl transferase ZDHHC5, which stimulates NADK activity. Fatty acids activate NADK by enhancing its palmitoylation and relief of an autoinhibitory function inherent to its amino terminus. Furthermore, ZDHHC5-/- mice showed defect in NADK palmitoylation and NADP+ production. Clinically, elevated expression of ZDHHC5 in pancreatic cancer patients was associated with increased NADK palmitoylation and correlated with poor prognoses for patients. These data reveal that fatty-acid and ZDHHC5-mediated palmitoylation has a critical role in NADP+ synthesis and cancers.

cancer biology↗

bioRxiv2025

Netrin-1 promotes pancreatic tumorigenesis and innervation through NEO1.

Nerves have been shown to regulate cancer progression. However, a clear demonstration of a role for axon guidance molecules in pancreatic tumorigenesis, innervation, and metastasis has been lacking. Using murine KrasG12D-mutant pancreatic organoids, we screened axon guidance molecules by qRT-PCR, identified Ntn1 upregulation, and then verified its in vivo upregulation during pancreatic tumorigenesis in humans and mice. NTN1 and its receptor NEO1 were upregulated in epithelial cells by the Kras mutation and {beta}-adrenergic signaling, in part, through the MAPK pathway. Ex-vivo culture of celiac ganglia showed that NTN1 promoted the axonogenesis of sympathetic neurons through the nerve NEO1 receptor. In the Pdx1-Cre;LSL-KrasG12D/+ model, Ntn1 knockout decreased sympathetic innervation and the development of pancreatic intraepithelial neoplasia. Treatment of pancreatic tumor organoids with recombinant NTN1 enhanced cell growth, epithelial-mesenchymal transition (EMT), and cancer stemness with the upregulation of ZEB1 and SOX9 through NEO1-mediated activation of focal adhesion kinase (FAK). In Pdx1-Cre;LSL-KrasG12D/+;LSL-Trp53R172H/+mice, Ntn1 knockout reduced innervation, FAK phosphorylation, and the features of EMT and stemness to extend mouse survival. In a liver metastasis model of PDAC (pancreatic ductal adenocarcinoma), treatment with a NTN1-neutralizing antibody or tumoral knockdown of Neo1 reduced ZEB1 and SOX9 and decreased tumor progression. In contrast, Ntn1 overexpression promoted innervation and the progression of PDAC liver metastasis. These data suggest that the NTN1/NEO1 axis is a key regulator of PDAC progression, directly influencing cancer cell stemness and EMT, while indirectly promoting tumor growth through nerves. Inhibiting the NTN1/NEO1 axis could represent a potential therapeutic approach for PDAC. Statement of SignificanceNTN1 promotes pancreatic tumorigenesis and metastasis directly and indirectly through nerves, highlighting the importance of tumor cell-nerve crosstalk in cancer. NTN1 blockade could represent a promising strategy for treating PDAC liver metastasis. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC="FIGDIR/small/666009v1_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@ca611corg.highwire.dtl.DTLVardef@ad9264org.highwire.dtl.DTLVardef@1661c00org.highwire.dtl.DTLVardef@b86798_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2025

Short RFamide and CFamide peptides as novel positive modulators of Acid-Sensing Ion Channel 3 with similar potentiating effects but different reversibility

Acid-sensing ion channels (ASICs) are members of the DEG/ENaC family that includes the only known peptide-gated ion channels. While ASICs are gated by protons, they have kept sensitivity to peptides and are notably modulated by the molluscan FMRFamide and other related mammalian neuropeptides ending by the RFamide motif. Screening efforts have been made to identify and characterize natural peptides able to modulate ASICs activity, and some peptides from different species are already known to modulate ASIC1a, ASIC1b and ASIC3. We identified here a set of synthetic short amidated hexapeptides, initially designed thirty years ago for their ability to inhibit the Na/Ca exchanger, as potent and selective positive modulators of the ASIC3 acid-induced activity. We focused on two of them, a RFamide peptide (FRCCRFamide) and a CFamide peptide (FR[C][R][C]Famide), demonstrating that they have similar specificity for and effects on ASIC3. The potentiating effects of the two peptides are due to a strong slow-down of the current desensitization, leading to an increase in the amount of current induced by acid pH ([≤]pH6.6), with apparent affinities ranging from 1 to 5 {micro}M. Surprisingly, the washout kinetic for the FR[C][C]RFamide peptide was much slower than those of FR[C][R][C]Famide and other known RFamide peptides, suggesting potential differences in their mechanisms of action. Computational modeling and structure-function analysis reveal interactions of both peptides with the non-proton binding site of ASIC3 initially identified for the synthetic compound GMQ (2-guanidine-4-methylquinazoline), as already reported before for other RFamide peptides, but our data also suggest possible additional effects of FR[C][C]RFamide involving directly or indirectly the proton binding domain. These findings expand our understanding of peptide modulation of ASIC channels and identify novel pharmacological tools selective among ASICs for investigating ASIC3 function.

pharmacology and toxicology↗