Biology subjects

Gonzalez, D.

Publications and source records attributed to Gonzalez, D..

At least 19 recordsLinked to original sources

bioRxiv2026

Mutualisms as engines for rapid adaptation: Rhizobium evolution facilitates plant drought resistance

Mutualisms play critical roles in organismal stress tolerance; yet environmental stressors may simultaneously alter the evolution of the mutualism itself. Stress may have particularly strong impacts on the evolution of microbial mutualists due to their capacity for rapid genetic change. Here we used a legume-rhizobia mutualism, in which plants exchange carbon for symbiotically fixed nitrogen, to evaluate how mutualisms evolve in response to stressors. We experimentally evolved populations of Rhizobium leguminasarum in a full factorial design, manipulating drought and nitrogen. We quantified genomic changes in Rhizobium populations as well as their quality as partners with their plant host, Trifolium repens. Drought selected for context- dependent stress benefits to the host; drought-adapted Rhizobium strains provided increased benefits to the host under drought, but fewer benefits to the host in well-watered environments. Conversely, nitrogen fertilization selected for decreased Rhizobium partner quality. Comparative genomics indicated that selection on standing structural variants along the symbiotic plasmid may underpin these drought benefits, specifically along genes associated with desiccation tolerance. These results suggest that stress can expand the benefits rhizobia provide to their legume hosts beyond nitrogen fixation, with rapid symbiont evolution an engine in promoting adaptive plant phenotypes. SIGNIFICANCE STATEMENTWhile mutualisms are fundamental to ecosystem functioning, they are often assumed to break down under environmental stress. We showed the opposite can happen. Here, we factorially manipulated drought stress and nitrogen fertilization and experimentally evolved a model legume-rhizobia mutualism, where rhizobial-bacteria trade nitrogen for plant carbon. When droughted, the symbiotic bacteria rapidly evolved new traits that made them better partners under drought, improving plant growth within just a few generations. Evolution occurred mainly on a specialized bacterial plasmid, a mobile piece of DNA distinct from the main genome. By contrast, added nitrogen fertilizer led to decreases in bacterial benefits. These findings suggest that mutualisms are not simply fragile in the face of global change, but can expand mutualistic benefits to buffer partners against stress. CLASSIFICATIONBiological Sciences, Evolution

evolutionary biology↗

bioRxiv2026

Airway Diameter-Matched Injury Improves Severity and Reproducibility of Experimental Rabbit Tracheal Stenosis

ObjectiveReliable animal models of tracheal stenosis are necessary for the development and translational testing of anti-fibrotic and regenerative therapies, but existing rabbit models frequently demonstrate substantial variability in stenosis severity, which limits their translational utility. The objective of our study was to determine whether airway diameter-matched mechanical injury improves the severity and reproducibility of experimental tracheal stenosis in a rabbit model, and to evaluate whether rabbit body weight is a reliable surrogate for tracheal luminal diameter during model creation. MethodsFourteen male New Zealand White rabbits (weight range, 2.7-3.5 kg) underwent tracheal injury using steel-bristle brushes introduced through a tracheotomy. Animals were assigned to receive either airway diameter-matched injury, in which brush size was selected to closely approximate the directly measured tracheal lumen diameter, or non-matched injury, in which brush size was selected without regard to measured lumen diameter. At postoperative day 21 (POD21), the injured tracheal segment and a native uninjured segment from the same animal were harvested and compared. Stenosis degree was quantified grossly, and lamina propria-to-cartilage (LP:C) ratio was quantified histologically by three blinded reviewers. The relationship between rabbit weight and airway diameter was assessed, and inter-rater reliability was calculated using the intraclass correlation coefficient (ICC). ResultsTwelve of fourteen rabbits reached the POD21 endpoint; two were euthanized early for severe airway compromise meeting humane endpoint criteria, both with approximately 80% stenosis. Injured tracheas demonstrated significantly greater stenosis than native controls (66.0 {+/-} 13.0% vs 16.0 {+/-} 2.7%; p = 0.00012), with a corresponding increase in LP:C ratio (p = 0.031). Airway diameter-matched injury produced significantly greater stenosis than non-matched injury (74.6 {+/-} 6.1% vs 50.6 {+/-} 4.0%; p = 0.001), while LP:C ratio did not differ between injury techniques (p = 1.0). Rabbit weight did not correlate with airway diameter (r = 0.176, p = 0.515; R2 = 0.031). Inter-rater reliability was excellent for both stenosis degree (ICC = 0.989) and LP:C ratio (ICC = 0.992). ConclusionsDirect measurement and matching of injury instrument diameter to native airway diameter substantially improves both the severity and the reproducibility of stenosis in a rabbit tracheal injury model, whereas body weight is an unreliable surrogate for airway size. This optimized, standardized protocol offers a reproducible platform for future translational studies of airway fibrosis and anti-fibrotic or regenerative therapies.

cell biology↗

bioRxiv2026

Reciprocal regulatory interactions between class I TCP transcription factors and ABA signaling balance growth and stress responses in Arabidopsis

Abscisic acid (ABA) plays a critical role in regulating plant responses to abiotic stress by modulating various physiological processes through complex molecular networks. TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTORS (TCP) transcription factors are known developmental regulators, but their roles in ABA signaling and abiotic stress responses remain poorly understood. We addressed this question by analyzing the closely related Arabidopsis thaliana class I TCPs TCP14 and TCP15 using a variety of genetic and molecular approaches. We found that TCP14 and TCP15 negatively influence ABA and salt stress responses. They function by directly activating genes encoding negative regulators of ABA signaling, such as ABA-INSENSITIVE FIVE-BINDING PROTEIN 2 (AFP2), thereby suppressing the expression of ABA-INSENSITIVE 5 (ABI5) and downstream ABA-responsive genes to inhibit ABA responses under non-stressful conditions. Notably, the TCPs are targets of ABA-mediated regulation, as ABA negatively affects TCP14 and TCP15 protein abundance, providing a mechanism to limit TCP-dependent transcriptional growth responses and de-repress ABA-signaling pathways during times of stress. We propose that the antagonistic interplay between class I TCPs and ABA may serve to fine-tune plant growth and stress responses according to environmental conditions, positioning TCP14 and TCP15 as crucial players in balancing plant developmental progression and stress adaptation.

Plant Biology↗

bioRxiv2026

RNase E resolves toxic condensates by counteracting phase separation of Type II RhlB helicases

In many Proteobacteria, the RNA helicase RhlB is a component of the RNA degradosome, a multi-protein complex involved in RNA processing and degradation. Within this complex, RhlB interacts with the scaffold endoribonuclease RNase E. In Escherichia coli, allosteric activation of RhlB by RNase E has defined the current paradigm for RhlB regulation. Here we identify a distinct clade of RhlB helicases, exemplified by Pseudomonas aeruginosa RhlB, which we designate Type II. Unlike Type I RhlB, Type II RhlB helicases contain an N-terminal intrinsically disordered region that drives RNA-dependent liquid-liquid phase separation and enhances RhlB activity. Biochemical, structural, and functional analyses show that P. aeruginosa RNase E binds RhlB through an interface distinct from that described in the E. coli model and, rather than stimulating activity, antagonizes RhlB phase separation. Excessive RhlB condensation impairs bacterial growth at low temperature, and RNase E-mediated control of RhlB condensation maintains growth under these conditions. Together, these findings reveal that conserved RNA degradosome components can engage in distinct regulatory interactions across species and identify condensate dissolution as a novel mechanism regulating RNA helicase activity.

microbiology↗

bioRxiv2026

scprocess: a pipeline for processing, integrating and visualising atlas-scale single cell data

MotivationThe transition toward "atlas-scale" single cell research has resulted in datasets comprising millions of cells across hundreds of samples, creating significant challenges for data management, computational efficiency, and reproducibility. While numerous methods are available for individual steps in single cell data processing, the highly complex nature of the analysis makes it challenging to maintain a clear record of every tool and parameter used. This makes final results difficult to reproduce, highlighting the need for a unified workflow that integrates multiple steps into a cohesive framework. Resultsscprocess is a Snakemake pipeline designed to streamline and automate the complex steps involved in processing single cell RNA sequencing data. Specifically optimized for data generated using the 10x Genomics technology, it provides a comprehensive solution that transforms raw sequencing files into standardized outputs suitable for a variety of downstream tasks. The pipeline is built to support the analysis of datasets comprising multiple (e.g. 100+) samples via a simple CLI, allowing researchers to efficiently explore their datasets while ensuring reproducibility and scalability in their workflows. Availability and implementationscprocess can be installed via GitHub (https://github.com/marusakod/scprocess) under the MIT license. Documentation, including setup instructions and tutorials on example datasets is available at https://marusakod.github.io/scprocess/.

bioinformatics↗

bioRxiv2026

Accurate haplotype-resolved de novo assembly of human genomes with RFhap

Haplotype-resolved de novo assemblies enable genome-wide separation of maternal and paternal variation, improving the interpretation of complex variants relevant to human disease. Trio-aware assemblers such as Hifiasm-Trio leverage parental short reads by deriving parent-specific k-mers to guide phasing within the long-read assembly graph; however, fixed k-mer length and heuristics cannot be optimal in the presence of sequencing errors and graph complexity in repetitive regions, contributing to phasing errors and reduced haplotype-resolved contiguity. Here we present RFhap, a trio-based long-read phasing method that integrates multi-k-mer parent-specific markers with an alignment-free k-mer lookup engine and a random forest classifier to assign long reads to maternal, paternal, or unknown haplotypes prior to de novo assembly. We benchmarked RFhap on four human trio datasets from the Human Pangenome project spanning two ONT chemistries (R10.4 and R9.4.1). Using Merqury to evaluate downstream assemblies, RFhap nearly doubled corrected haplotype NG50 (mean 24.3 Mb vs 13.1 Mb) and halved switch error rates (mean 0.111% vs 0.236%) relative to Hifiasm-Trio, while remaining competitive in consensus QV and parental k-mer completeness. Consistent with improved phasing, RFhap reduced long-switch errors by [~]3-fold across datasets, particularly within interspersed repeats. Together, these results demonstrate that RFhap improves phasing accuracy from standard trio data, representing a step toward accurate and automated diploid human de novo assembly from long reads.

bioinformatics↗

bioRxiv2025

Cell surface localization and intercellular transfer of the hantavirus nucleocapsid protein via a viral assembly-independent mechanism

Hantaviruses are segmented negative-sense RNA viruses that package their genome into helical ribonucleocapsids, by oligomerization of the nucleocapsid (N) protein along the viral RNA. Upon transmission to humans, hantaviruses can cause severe disease characterized by increased vascular permeability in the microvasculature, a key driver of pathogenesis. In patients and rodent reservoirs, robust and persistent antibody responses against the nucleocapsid (N) protein are consistently observed. Here we investigated whether the hantavirus N protein, described as a strictly intracellular protein, is released into the extracellular environment during viral infection. By using diverse experimental approaches, we demonstrate that in cells infected with Andes virus (ANDV) or the non-pathogenic Tula virus (TULV), the N protein localizes on the plasma membrane. Transfection experiments further revealed that the surface localization of N proteins from Murine, Arvicoline, Neotomine and Sigmodontine rodent-reservoir-associated hantaviruses did not require co-expression of other viral proteins indicating that its trafficking to the cell surface is mediated by a mechanism distinct from canonical virion assembly pathways. Moreover, we show that the N protein is secreted from cells into the extracellular milieu and is further transferred to neighboring cells. Interestingly, despite being present on the cell surface and secreted into the extracellular media, the TULV N protein transfer of the N protein to neighboring cells was significantly lower compared to that of ANDV N protein. The extracellular presence of hantavirus N proteins, and likely also from other clinically-relevant bunyaviruses, unveils new possible functions of the protein during the viral infection cycle, which is likely related to immune responses, immune modulation and viral pathogenesis.

microbiology↗

bioRxiv2025

Investigating the Impact of Omental Adipocytes on Ovarian Cancer: Insights from a 3D in-silico model

1Ovarian cancer is responsible for the most deaths of all gynaecological cancers in the Western world [1]. The symptoms of ovarian cancer are typically subtle and alike to less lethal diseases found more prevalently in the population, frequently resulting in late diagnoses and advanced tumour stages upon treatment initiation [2]. While surgery and platinum-based treatments can be curative, ovarian cancers found at the latter, metastasised stages are likely to be recurrent and more tailored towards palliative care [3]. Metastasised ovarian cancer spreads to surrounding organs and tissues such as the greater omentum [4], a large fat pad composed of adipose tissue stretching from the stomach and hanging over the intestines. The location of this is key in its role towards ovarian cancer and its progression [5]. In this study, we develop a mathematical model to investigate the role that adipocytes found in adipose tissue can have in ovarian cancer progression. Observations of biological experiments from two cell lines create foundations to build a multiscale agent-based model in a Physicell framework. The impact of the adipose derived media concentration, treatment dosage, and initial tumour size are explored to find how these conditions affect the spatio-temporal dynamics of cancer tumours.

cancer biology↗

bioRxiv2025

Fibroblast contractility drives network reorganization and epithelial proliferation in intestinal polyposis

Fibroblasts are critical regulators of epithelial homeostasis through mechanics and signaling. However, the regulatory principles governing fibroblast behaviors are largely unknown. Fibroblast dysregulation has emerged as a pathological contributor in epithelial diseases such as intestinal polyposis. Here, using an inducible Bmp-loss-of-function polyposis model, we define stepwise mechanisms unraveling how dysregulated signaling perturbs fibroblast behaviors, which in turn, disrupt their function to regulate epithelial homeostasis. Intriguingly, the first initiating event leading to epithelial polyps was architectural and impacted the fibroblasts, not the epithelium. Bmp signaling inhibition caused fibroblasts to become hypercontractile, leading to their reorganization from an elaborate network into collapsed clusters beneath crypts. Disrupted fibroblast mechanics and compartmentalization preceded epithelial hyperproliferation in polyps. Using in vitro models, we show that fibroblast hypercontractility not only disrupted fibroblast organization, but also enhanced the ability of fibroblasts to support epithelial growth, leading to epithelial dysregulation. Overall, our studies reveal stepwise regulatory mechanisms underlying fibroblast signaling, mechanics and organization critical for their function to regulate epithelial homeostasis.

cell biology↗

bioRxiv2025

Enhanced CB1 receptor function in GABAergic neurons mediates hyperexcitability and impaired sensory-driven synchrony of cortical circuits in Fragile X Syndrome model mice

Electroencephalographic (EEG) recordings in individuals with Fragile X Syndrome (FXS) and the mouse model of FXS (Fmr1 KO) display cortical hyperexcitability at rest, as well as deficits in sensory-driven cortical network synchrony. A form of circuit hyperexcitability is observed in ex vivo cortical slices of Fmr1 KO mice as prolonged persistent activity, or Up, states. It is unknown if the circuit mechanisms that cause prolonged Up states contribute to FXS-relevant EEG phenotypes. Here we examined the role of endocannabinoids (eCB) in prolonged Up states in slices and resting and sensory-driven EEG phenotypes in awake Fmr1 KO mice. Bidirectional changes in eCB function are reported in the Fmr1 KO that depend on synapse type (excitatory or inhibitory). We demonstrate that pharmacological or genetic reduction of Cannabinoid Receptor 1 (CB1R) in GABAergic neurons rescues prolonged cortical Up states and deficits in sensory-driven cortical synchrony in Fmr1 KO mice. In support of these findings, recordings from Fmr1 KO cortical Layer (L) 2/3 pyramidal neurons revealed enhanced CB1R-mediated suppression of inhibitory synaptic currents. In contrast, genetic reduction of Cnr1 in glutamatergic neurons did not affect Up state duration, but deletion of Fmr1 in the same neurons was sufficient to cause long Up states. These findings support a model where loss of Fmr1 in glutamatergic neurons leads to enhanced CB1R-mediated suppression of GABAergic synaptic transmission, prolonged cortical circuit activation and reduced sensory-driven circuit synchronization. Results suggest that antagonism of CB1Rs as a therapeutic strategy to correct sensory processing deficits in FXS.

neuroscience↗

bioRxiv2024

Critical functions and key interactions mediated by the RNase E scaffolding domain in Pseudomonas aeruginosa

The RNA degradosome is a bacterial multi-protein complex mediating mRNA processing and degradation. In Pseudomonadota, this complex assembles on the C-terminal domain (CTD) of RNase E through short linear motifs (SLiMs) that determine its composition and functionality. In the human pathogen Pseudomonas aeruginosa, the RNase E CTD exhibits limited similarity to that of model organisms, impeding our understanding of RNA metabolic processes in this bacterium. Our study systematically maps the interactions mediated by the P. aeruginosa RNase E CTD and highlights its critical role in transcript regulation and cellular functions. We identified the SLiMs crucial for membrane attachment, RNA binding and complex clustering, as well as for direct binding to the core components PNPase and RhlB. Transcriptome analyses of RNase E CTD mutants revealed altered expression of genes involved in quorum sensing, type III secretion, and amino acid metabolism. Additionally, we show that the mutants are impaired in cold adaptation, pH response, and virulence in an infection model. Overall, this work establishes the essential role of the RNA degradosome in driving bacterial adaptability and pathogenicity. Author summaryBacteria must rapidly adapt to changing environments, whether facing temperature shifts, nutrient scarcity, or antibiotic exposure. A key mechanism enabling this adaptability is the regulation of mRNA levels--the molecular blueprints for protein production. This process is governed by the RNA degradosome, a multi-protein complex that processes and degrades RNA to control gene expression. Although the RNA degradosome core function is conserved across bacteria, its composition and organization differ significantly between species, reflecting diverse lifestyles and environmental challenges each bacterium encounter. In this study, we investigated the RNA degradosome in Pseudomonas aeruginosa, a bacterial pathogen causing difficult-to-treat infections in humans. We identified its components and mapped regions within the complex essential for RNA binding, membrane attachment, and spatial organization. Disrupting these regions compromised P. aeruginosa ability to survive in cold conditions, respond to stress, and establish an infection. Through this work, we uncovered unique features of the P. aeruginosa RNA degradosome that distinguish it from those of other species, emphasizing the RNA degradosome critical role in bacterial adaptability and highlight it as a promising target for therapies against P. aeruginosa infections.

microbiology↗

bioRxiv2024

Nerve-associated macrophages control adipose homeostasis across lifespan and restrain age-related inflammation

Age-related inflammation or inflammaging is a key mechanism that increases disease burden and may control lifespan. How adipose tissue macrophages (ATMs) control inflammaging is not well understood in part because the molecular identities of niche-specific ATMs are incompletely known. Using intravascular labeling to exclude circulating myeloid cells and subsequent single-cell sequencing with orthogonal validation, we define the diversity and alterations in niche resident ATMs through lifespan. Aging led to depletion of vessel-associated macrophages (VAMs), expansion of lipid-associated macrophages (LAMs), and emergence of a unique subset of CD38+ age-associated macrophages (AAMs) in visceral white adipose tissue (VAT). Interestingly, CD169+CD11c- ATMs are enriched in a subpopulation of nerve-associated macrophages (NAMs) that declines with age. Depletion of CD169+ NAMs in aged mice increases inflammaging and impairs lipolysis suggesting that they are necessary for preventing catecholamine resistance in VAT. These findings reveal specialized ATMs control adipose homeostasis and link inflammation to tissue dysfunction during aging.

immunology↗

bioRxiv2024

Exploring the role of EMT in Ovarian Cancer Progression: Insights from a multiscale mathematical model

Epithelial-to-mesenchymal transition (EMT) plays a key role in the progression of cancer tumours and can make treatment significantly less successful for patients. EMT occurs when a cell gains a different phenotype and possesses different behaviours to those previously exhibited. This may result in enhanced drug resistance, higher cell plasticity, and increased metastatic abilities. It has therefore has become essential to encapsulate this change and study tumour progression and its response to treatments. Here, we use a 3D agent-based multiscale modelling framework based on Physicell to investigate the role of EMT over time in two cell lines, OVCAR-3 and SKOV-3. The impact of conditions in the microenvironment are incorporated into the model by modifying cellular behaviours dependant on variables such as substrate concentrations and proximity to neighbouring cells. OVCAR-3 and SKOV-3 cell lines possess highly contrasting tumour layouts, allowing a vast array of different tumour dynamics and morphologies to be tested and studied. The model encapsulates the biological observations and trends seen in tumour growth and development, thus can help to obtain further insights into OVCAR-3 and SKOV-3 cell line dynamics. Sensitivity analysis was performed to investigate the impact of parameter sensitivity on model outcome. Sensitivity analysis showed that parameters used in generating the rate of EMT and cycle rates within the cells are relatively more sensitive than other parameters used.

cancer biology↗

bioRxiv2024

Nerve injury downregulates δ-opioid and cannabinoid CB1 receptor genes through REST in primary sensory neurons

The transcription repressor REST in the dorsal root ganglion (DRG) is upregulated by peripheral nerve injury and promotes the development of chronic pain. However, the genes targeted by REST in neuropathic pain development remain unclear. The expression levels of 4 opioid receptor (Oprm1, Oprd1, Oprl1, Oprk1) and the cannabinoid CB1 receptor (Cnr1) genes in the DRG regulate nociception. In this study, we determined the role of REST in the control of their expression in the DRG induced by spared nerve injury (SNI) in both male and female mice. Transcriptomic analyses of male mouse DRGs followed by quantitative reverse transcription polymerase chain reaction analyses of both male and female mouse DRGs showed that SNI upregulated expression of Rest and downregulated mRNA levels of all 4 opioid receptor and Cnr1 genes, but Oprm1 was upregulated in female mice. Analysis of publicly available bioinformatic data suggested that REST binds to the promoter regions of Oprm1 and Cnr1. Chromatin immunoprecipitation analyses indicated differing levels of REST at these promoters in male and female mice. Full-length Rest conditional knockout in primary sensory neurons reduced SNI-induced pain hypersensitivity and rescued the SNI-induced reduction in the expression of Oprd1 and Cnr1 in the DRG in both male and female mice. Our results suggest that nerve injury represses the transcription of Oprd1 and Cnr1 via REST in primary sensory neurons and that REST is a potential therapeutic target for neuropathic pain.

neuroscience↗

bioRxiv2023

A ubiquitous Microcoleus species causes benthic cyanotoxic blooms worldwide

Recently, proliferations of benthic cyanobacteria producing derivatives of anatoxin-a have been reported in rivers all over the world. In three river systems, in New Zealand, the USA, and Canada, a cohesive cluster of Microcoleus strains was responsible for toxin production. Here, we document a similar toxigenic event that occurred at the mouth of the river Areuse in lake Neuchatel (Switzerland) and caused the death of several dogs. Using 16S RNA-based community analysis, we show that riverine benthic communities are dominated by Oscillatoriales and especially by Microcoleus strains. We correlate the detection of one sequence variant with the presence of anatoxin-a derivatives and use metagenomics to assemble a complete circular genome of the strain. The strain is distinct from the ones isolated in New Zealand, the USA, and Canada, but belongs to the same species; it shares significant traits with them, in particular a relatively small genome and incomplete vitamin biosynthetic pathways. Overall, our results suggest that the major anatoxin-a-associated benthic proliferations worldwide can be traced back to a single ubiquitous species, Microcoleus anatoxicus, rather than to a diversity of cyanobacterial lineages. We recommend that this species be monitored internationally in order to help predict and mitigate similar cyanotoxic events.

microbiology↗

bioRxiv2023

Diurnal cycles drive rhythmic physiology and promote survival in facultative phototrophic bacteria

Bacteria have evolved many strategies to spare energy when nutrients become scarce. One widespread such strategy is facultative phototrophy, which helps heterotrophs supplement their energy supply using light. Our knowledge on the impact that such behaviors have on bacterial fitness and physiology is, however, still limited. Here, we study how a representative of the genus Porphyrobacter, in which aerobic anoxygenic phototrophy is ancestral, responds to different light regimes under nutrient limitation. We show that bacterial survival in stationary phase relies on functional reaction centers and varies depending on the light regime. Under dark-light alternance, our bacterial model presents a diphasic life history dependent on phototrophy: during dark phases, the cells inhibit DNA replication and part of the population lyses and releases nutrients, while subsequent light phases allow for the recovery and renewed growth of the surviving cells. We correlate these cyclic variations with a pervasive pattern of rhythmic transcription which reflects global changes in diurnal metabolic activity. Finally, we demonstrate that, compared to either a phototrophy null mutant or a bacteriochlorophyll a overproducer, the wild type strain is better adapted to natural environments, where regular dark-light cycles are interspersed with additional accidental dark episodes. Overall, our results highlight the importance of light-induced biological rhythms in a new model of aerobic anoxygenic phototroph representative of an ecologically important group of environmental bacteria.

microbiology↗

bioRxiv2023

Female specific dysfunction of sensory neocortical circuits in a mouse model of autism mediated by mGluR5 and Estrogen Receptor α

Autism manifests differently in males and females and the brain mechanisms that mediate these sex-dependent differences are unknown. Here, we demonstrate that deletion of the ASD-risk gene, Pten, in neocortical pyramidal neurons (NSEPten KO) results in robust hyperexcitability of local neocortical circuits in female, but not male, mice, observed as prolonged, spontaneous persistent activity states (UP states). Circuit hyperexcitability in NSEPten KO mice is mediated by enhanced and/or altered signaling of metabotropic glutamate receptor 5 (mGluR5) and estrogen receptor (ER) to ERK and protein synthesis selectively in Pten deleted female neurons. In support of this idea, Pten deleted Layer 5 cortical neurons have female-specific increases in mGluR5 and mGluR5-driven protein synthesis. In addition, mGluR5-ER complexes are elevated in female cortex and genetic reduction of ER in Pten KO cortical neurons rescues circuit excitability, protein synthesis and enlarged neurons selectively in females. Abnormal timing and hyperexcitability of neocortical circuits in female NSEPten KO mice are associated with deficits in temporal processing of sensory stimuli and social behaviors as well as mGluR5-dependent seizures. Female-specific cortical hyperexcitability and mGluR5-dependent seizures are also observed in a human disease relevant mouse model, germline Pten+/- mice. Our results reveal molecular mechanisms by which sex and a high impact ASD-risk gene interact to affect brain function and behavior.

neuroscience↗

bioRxiv2023

Antibiotic potentiation and inhibition of cross-resistance in pathogens associated with cystic fibrosis

Critical Gram-negative pathogens, like Pseudomonas, Stenotrophomonas and Burkholderia, have become resistant to most antibiotics. Complex resistance profiles together with synergistic interactions between these organisms increase the likelihood of treatment failure in distinct infection settings, for example in the lungs of cystic fibrosis (CF) patients. Here, we discover that cell envelope protein homeostasis pathways underpin both antibiotic resistance and cross-protection in CF-associated bacteria. We find that inhibition of oxidative protein folding inactivates multiple species-specific resistance proteins. Using this strategy, we sensitize multidrug-resistant Pseudomonas aeruginosa to {beta}-lactam antibiotics and demonstrate promise of new treatment avenues for the recalcitrant emerging pathogen Stenotrophomonas maltophilia. The same approach also inhibits cross-protection between resistant S. maltophilia and susceptible P. aeruginosa, allowing eradication of both commonly co-occurring CF-associated organisms. Our results provide the basis for the development of next-generation strategies that target antibiotic resistance, while also impairing specific interbacterial interactions that enhance the severity of polymicrobial infections.

microbiology↗