Biology subjects

Castro, M.

Publications and source records attributed to Castro, M..

At least 19 recordsLinked to original sources

bioRxiv2026

Circadian and Sex-Specific Responses to Alternaria alternata in Allergic Airway Inflammation

Asthma severity and immune responses are regulated by circadian rhythms, yet the role of circadian timing in fungal allergen-induced airway inflammation remains poorly defined. Alternaria alternata, a clinically relevant fungal allergen, is strongly associated with severe asthma exacerbations and persistent airway dysfunction. Using a preclinical mouse model, we investigated whether pulmonary responses to Alternaria exposure are influenced by time of day and sex. We demonstrate that Alternaria induces allergic airway inflammation, airway hyperresponsiveness (AHR), and epithelial barrier disruption in a circadian- and sex-dependent manner. Female mice exhibited enhanced eosinophilic, neutrophilic, interstitial macrophage, and dendritic cell infiltration predominantly at Zeitgeber Time 0 (ZT0), whereas males showed stronger inflammatory responses at ZT12. Alternaria exposure increased IL-33 release and promoted ILC2 and Th2 cell accumulation, with distinct temporal patterns between sexes. Cytokine and chemokine profiling revealed robust Th2, proinflammatory, and Th17 responses that varied with exposure time, with higher responses at ZT12 in females and ZT0 in males. Markers of tissue injury, including lactate dehydrogenase and uric acid, followed similar circadian-dependent trends. Functionally, Alternaria-exposed mice displayed greater AHR during the resting phase, particularly in males. Additionally, Alternaria disrupted epithelial junctional proteins (E-cadherin and ZO-1) and altered expression of core circadian clock proteins CLOCK, BMAL1, and REV-ERB. Mechanistically, peak inflammation coincided with enhanced STAT1, STAT3, and STAT6 activation. Collectively, these findings identify circadian timing and sex as key determinants of fungal allergen-induced airway inflammation and suggest chronotherapeutic approaches may improve asthma outcomes.

immunology↗

bioRxiv2026

SWELL1 channel-mediated D-2HG export promotes immune evasion and metabolic fitness in IDH-mutant gliomas

Isocitrate dehydrogenase (IDH) is the most frequently mutated metabolic enzyme in human cancers. Mutant IDH produces the oncometabolite D-2-hydroxyglutarate (D-2HG), which promotes tumorigenesis in part through epigenetic alterations. Beyond its cell-autonomous effects, tumor-derived D-2HG acts as a potent immunosuppressant that establishes an immune-cold tumor microenvironment. However, the mechanism by which D-2HG is released from tumors remains largely unknown. Here, we identify the SWELL1 (LRRC8A)/LRRC8C-containing volume-regulated anion channel (VRAC) as a principal pathway for D-2HG efflux from IDH-mutant cells. Genetic deletion of SWELL1, the essential VRAC subunit, markedly reduces D-2HG release and reverses associated immunosuppression in an orthotopic mouse model of IDH-mutant glioma. Strikingly, loss of VRAC causes intracellular accumulation of D-2HG, which paradoxically limits tumor cell proliferation by driving epigenetic remodeling and mitochondrial metabolic stress. Pharmacological inhibition of VRAC with dicumarol suppresses IDH-mutant glioma growth, enhances intratumoral T cell activation, synergizes with immune checkpoint blockade, and prolongs survival in tumor-bearing mice. In human IDH-mutant lower-grade gliomas, elevated LRRC8C expression correlates with DNA hypermethylation and an immunosuppressive tumor microenvironment (TME), and predicts poor overall survival. Together, these findings establish VRAC-mediated D-2HG export as a central mechanism regulating both immune evasion and tumor cell fitness, uncovering new therapeutic opportunities across IDH-mutant cancers.

cancer biology↗

bioRxiv2026

Emergent catch bonds from slip-like contacts: cooperative force-driven proofreading at receptor--ligand interfaces

Mechanical forces modulate receptor-ligand kinetics, sometimes producing the so-called catch bond: a tensile force strengthens the bond, whereas in most cases engagement time is reduced (a slip bond). Multiple phenomenological models reproduce catch-slip behavior between receptors and ligands, primarily by positing how the reaction's free-energy landscape changes under applied forces. In this paper, we show that distinct microscopic mechanisms often collapse into mathematically equivalent multi-exponential forms. This operational equivalence makes them difficult to distinguish (or even falsify) based solely on bond survival curves. We expose this mathematical equivalence and the validity regimes of these reductions and introduce \emph{c}ooperative \emph{f}orce-driven \emph{p}roof\emph{r}eading (CFPR), a network-level mechanism where pulling geometry enables contact-zone reorganization and additional nucleation of residue binding contributions, generating emergent catch-like responses from individually slip-like residue binding contributions. Our model can incorporate data from molecular dynamics simulations to predict, in advance, whether catch-slip will be present in a system and under what conditions, making it a predictive tool that complements experimental data.

biophysics↗

bioRxiv2026

Vaccine imprinting drives increased SARS-CoV-2 variant infection in children

Virus exposure history, particularly first exposure, is believed to shape vaccine efficacy and infection susceptibility; however, evidence for mechanistic links between immune responses in individuals and epidemiological outcome in populations is scarce. Recent co-circulation of SARS-CoV-2 variants XFG and BA.3.2 has revealed a striking enrichment in BA.3.2 cases among children. By combining epidemiological modeling, serology and monoclonal antibody analysis in children and adults, we show the dependence of effective variant-specific antibodies on vaccination history which may explain birth-year influence on differential susceptibility to these co-circulating variants. Ancestral cross-reactive site I antibodies frequently neutralize BA.3.2, but not XFG. By contrast, Omicron type-specific site I/III and III antibodies frequently neutralize XFG but not BA.3.2, revealing a tradeoff in the ability to neutralize these two co-circulating strains. These findings mechanistically link immune history, variant neutralization, antibody repertoire and variant infection risk, and suggest that vaccination regimens in children should prioritize neutralization breadth.

immunology↗

bioRxiv2026

Antidepressant mechanism and treatment response define distinct hippocampal-amygdala circuit biomarkers during emotional memory in humans

Antidepressant efficacy varies widely, yet the circuit-level mechanisms that distinguish treatment responders from non-responders remain poorly understood in humans. Here, we used high-resolution neuroimaging of hippocampal-amygdala networks during an emotional mnemonic discrimination task that taxes hippocampal pattern separation to examine how antidepressant mechanism of action and perceived treatment response shape emotional memory circuitry (N = 117). Participants included individuals taking single-action antidepressants (selective serotonin reuptake inhibitors), multi-action antidepressants (serotonin-norepinephrine reuptake inhibitors, norepinephrine-dopamine reuptake inhibitors, or polypharmacy), and unmedicated controls matched on current depression severity. Antidepressant mechanism and treatment response were associated with distinct patterns of activity in hippocampal subfields (dentate gyrus (DG)/CA3 and CA1) and amygdala subnuclei, including the basolateral amygdala (BLA) and central amygdala (CEA), during emotional mnemonic discrimination. Among non-responders, the relative balance of hippocampal activity differed by antidepressant mechanism: those taking single-action antidepressants showed greater DG/CA3 than CA1 activity, whereas those taking multi-action antidepressants showed the opposite pattern. This suggests mechanistically specific differences in hippocampal computations associated with ineffective treatment. These effects were localized to the anterior hippocampus, with no significant effects observed in posterior regions. In contrast, responders exhibited stronger DG/CA3-BLA coactivation during negative mnemonic discrimination, a pattern absent in non-responders and unmedicated controls. Antidepressant-associated differences in amygdala subnuclei activity persisted beyond current symptom severity, suggesting medication-related modulation of emotional memory circuits rather than effects driven solely by depression severity. These findings provide evidence in humans that antidepressant use is associated with altered hippocampal-amygdala circuitry in a manner that depends on both pharmacological mechanism and treatment efficacy. Identifying circuit-level signatures of treatment response may inform mechanistically guided approaches to antidepressant selection and monitoring.

neuroscience↗

bioRxiv2026

The Central Nucleus of the Amygdala Encodes the Motivation to Pursue Ethanol

Prior studies implicate the central nucleus of the amygdala (CeA) in reward motivation, yet how this region encodes motivation for ethanol (EtOH) seeking and consumption-and how this compares to encoding of natural rewards--remains poorly understood. We recorded single-unit neural activity from rats during a cued instrumental task in which lever insertion on each trial indicates the opportunity to lever press for ethanol and post-press lever retraction signals ethanol delivery. We found neurons responsive to multiple trial events (lever insertion and retraction cues, lever press, port entry, and reward licks), including neurons with rhythmic activity entrained to licking during EtOH consumption. Notably, CeA neural responses to the lever insertion cue at trial start encoded both the likelihood and speed of engagement during reward seeking. Using a supervised classifier, we found that trial engagement and motivation level could be decoded from pre-trial and lever insertion response periods. Finally, we assessed whether these effects generalized to natural reward seeking. Sucrose-rewarded rats (both ethanol-exposed and ethanol-naive) showed higher motivation (more rewards earned and shorter first-press latencies) and stronger CeA recruitment and responses at lever insertion than ethanol-rewarded rats, in agreement with the notion that CeA circuits amplify reward-predictive cue signals to facilitate rapid action initiation under high motivational states. Together, these findings indicate that CeA neurons dynamically encode motivational states, with tonic activity and reward-predictive cue responses predicting both engagement in reward seeking and the vigor of action initiation. We suggest these patterns of neural activity drive ethanol and sucrose pursuit. Significance StatementHow motivational states drive reward-seeking is a central question in systems neuroscience, yet the mechanisms linking neural signals to action initiation remain poorly understood. Recording single-unit activity in the amygdala central nucleus (CeA) during cued ethanol self-administration revealed that neural responses to reward-predictive cues encoded both the decision to engage in reward seeking and the vigor of action initiation, and motivational state was decoded from cue-evoked signals and tonic activity even before cue presentation. Consistent with greater motivation for the more palatable sucrose reward, CeA neurons showed stronger cue responses and greater anticipatory firing preceding tongue contact with reward, compared with ethanol-rewarded rats. These findings identify CeA activity patterns that link motivational state to the rapid initiation of goal-directed action.

neuroscience↗

bioRxiv2026

Structural Dynamics of the Dopamine D2 Receptor with a Non-Basic Ligand

Progress in understanding protein-ligand interactions is revolutionizing drug design, especially for G protein-coupled receptors (GPCRs), which are targets for 35% of marketed drugs.1 The dopamine D2 receptor (D2R) represents a key drug target in schizophrenia and Parkinsons disease.2 While structural studies have clarified its interactions with classical ligands, the behavior of atypical, non-basic ligands like D2AAK2 remains unclear. Notably, D2AAK2 shows strong selectivity for D2R over the closely related D3R, despite identical binding pocket composition. Here, we present a cryo-EM structure of D2AAK2 bound to D2R, showing that aspartate 3.32 serves as the main anchoring point, even though the compound lacks a basic nitrogen atom. Using enhanced sampling molecular dynamics simulations and experimental approaches, we uncover a complex binding energy landscape. Simulations suggest that D2AAK2 receptor subtype selectivity between identical binding sites arises from different energy barriers for their conformational changes. Non-basic ligands offer advantages such as better brain penetration and improved pharmacokinetics.3,4 This study provides the first structural insights into a non-basic ligand targeting D2R, paving the way for developing more effective, selective drugs.

pharmacology and toxicology↗

bioRxiv2026

Distinctive spore architecture and developmental biology of Turicibacter sanguinis reveal unexpected diversity among gut spore formers

Sporulation is a widespread but incompletely characterized trait among gut commensals, where it underpins microbial persistence, transmission, and ecological resilience. Most insights into spore biology derive from Bacilli and Clostridia, yet little is known about sporulation in phylogenetically distant gut-associated lineages. Turicibacter sanguinis, a strict anaerobe linked to host serotonin metabolism, lipid homeostasis, and neurodegenerative disease, represents one such understudied taxon. Here, we integrate ultrastructural, physiological, and comparative genomic analyses to define the sporulation and germination program of T. sanguinis. We show that T. sanguinis forms heat-resistant spores with a canonical core-cortex-coat architecture but displays previously undescribed features including a dual-layered outer envelope and bimodal electron-dense coat morphotypes. Developmental stages of sporulation follow canonical stages of Bacillus- and Clostridium-like sporulation while genomic analyses reveal a hybrid regulatory architecture combining Clostridial-type Spo0A initiation with Bacillus-like late-stage sigma factor control. Germination assays and genomic signatures further indicate a nutrient-responsive, Bacillus-like pathway involving Ger-family receptors, SpoVA-mediated Ca-DPA release, and CwlJ- and SleM-type cortex hydrolases. Together, these findings identify T. sanguinis as a distinct spore-forming lineage within the human gut microbiota and expand the known diversity of sporulation strategies across the Firmicutes.

microbiology↗

bioRxiv2025

OrthoGuide: A database for rooting inference of orthologous genes

Orthology has proven to be a valuable proxy for the study of the evolution of biological systems, such as metabolic pathways and gene regulatory networks. Genes within the same orthologous group typically share the same evolutionary history, reflecting their common ancestry. To leverage this property, several tools and databases, most notably the COG database, have been developed to support evolutionary analyses based on orthology information. Building on these resources, we previously developed the Bridge algorithm to infer the evolutionary root of genes by analyzing the distribution of orthologous groups in a phylogenetic tree. Here, we introduce OrthoGuide, a database and web application that provides rooting information for all COGs across eight model species, as inferred by the Bridge algorithm. The web application and the database are hosted at https://dalmolingroup.imd.ufrn.br/orthoguide/. Significance StatementUnderstanding the evolutionary origin of genes is fundamental for systems biology but is often obstructed by computationally complex bioinformatic workflows. This creates a bottleneck for many researchers. OrthoGuide directly addresses this challenge by providing a public, pre-computed database of evolutionary rooting data for all genes across eight eukaryotic model organisms. Our web application eliminates the need for user-side computation. OrthoGuide delivers instant results as well as interactive visualizations. This resource democratizes access to evolutionary analyses based on orthology information, enabling a broader scientific community to rapidly translate simple gene lists into insights about the assembly of biological systems.

evolutionary biology↗

bioRxiv2025

Lambda N as a model substrate for studying the mechanism of Escherichia coli ATP-dependent protease Lon as a regulatory enzyme.

As an ATP-dependent protease, the quality control functions of Lon have been extensively studied and reviewed in the literature. By contrast, very little research has been conducted to investigate Lons physiological functions and its mechanism as a regulatory protease. In this manuscript, we provided a survey of literature and data to convey that the lambda N ({lambda}N) protein is a suitable Escherichia coli Lon (ELon) substrate for studying the role played by Lon in regulating an RNA transcription process. For proof of principle, we demonstrated that the minimal component of the RNA transcription complex containing RNA polymerase (RNAP) and the {sigma} factor can inhibit {lambda}N degradation by ELon through SDS-PAGE, and the carboxyl-terminal of {lambda}N is important for Lon competing with RNAP interaction. Using negative stain electron microscopy, we obtained structural evidence to show that {lambda}N lacking the carboxyl-terminal flanked by residues 99-107 interacted with ELon differently than full-length {lambda}N. Taken together, the activity and EM data provide a starting point for performing a physiological enzymology study on the contribution of ELon toward RNA transcription.

biochemistry↗

bioRxiv2024

YAP/TAZ signaling in allantois-derived cells is required for placental vascularization

Normal placental development and angiogenesis are crucial for fetal growth and maternal health during pregnancy. However, molecular regulation of placental angiogenesis has been difficult to study due to a lack of specific genetic tools that isolate the placenta from the embryo and yolk sac. To address this gap in knowledge we recently developed Hoxa13Cre mice in which Cre is expressed in allantois-derived cells, including placental endothelial and stromal cells. Mice lacking the transcriptional regulators Yes-associated protein (YAP) and PDZ-binding motif (TAZ) in allantois-derived cells exhibit embryonic lethality at midgestation with compromised placental vasculature. snRNA-seq analysis revealed transcriptional changes in placental stromal cells and endothelial cells. YAP/TAZ mutants exhibited significantly reduced placental stromal cells prior to the endothelial architectural change, highlighting the role of these cells in placental vascular growth. These results reveal a central role for YAP/TAZ signaling during placental vascular growth and implicate Hoxa13-derived placental stromal cells as a critical component of placental vascularization.

developmental biology↗

bioRxiv2024

Collective effects in the population growth of microbials

We investigate the growth dynamics of microbial populations, challenging the conventional logistic model. By analyzing empirical data from various biomes, we demonstrate that microbial growth is better described by a generalized logistic model, the{theta} -logistic model. This accounts for different growth mechanisms and environmental fluctuations, leading to a generalized gamma distribution of abundance fluctuations. Our findings reveal that microbial growth is never sublinear, so they cannot endorse--at least in the microbial world--the recent proposal of this mechanism as a stability enhancer of highly diverse communities. These results have significant implications for understanding macroecological patterns and the stability of microbial ecosystems.

bioinformatics↗

bioRxiv2024

Peptide-enabled ribonucleoprotein delivery for CRISPR engineering (PERC) in primary human immune cells and hematopoietic stem cells

Peptide-enabled ribonucleoprotein delivery for CRISPR engineering (PERC) is a new approach for ex vivo genome editing of primary human cells. PERC uses a single amphiphilic peptide reagent to mediate intracellular delivery of the same pre-formed CRISPR ribonucleoprotein enzymes that are broadly used in research and therapeutics, resulting in high-efficiency editing of stimulated immune cells and cultured hematopoietic stem and progenitor cells (HSPCs). PERC facilitates nuclease-mediated gene knockout, precise transgene knock-in, and base editing. PERC involves mixing the CRISPR ribonucleoprotein enzyme with peptide and then incubating the formulation with cultured cells. For efficient transgene knock-in, adeno-associated virus (AAV) bearing homology-directed repair template DNA may be included. In contrast to electroporation, PERC is appealing as it requires no dedicated hardware and has less impact on cell phenotype and viability. Due to the gentle nature of PERC, delivery can be performed multiple times without substantial impact to cell health or phenotype. Here we report methods for improved PERC-mediated editing of T cells as well as novel methods for PERC-mediated editing of HSPCs, including knockout and precise knock-in. Editing efficiencies can surpass 90% using either Cas9 or Cas12a in primary T cells or HSPCs. Because PERC calls for only three readily available reagents - protein, RNA, and peptide - and does not require dedicated hardware for any step, PERC demands no special expertise and is exceptionally straightforward to adopt. The inherent compatibility of PERC with established cell engineering pipelines makes this approach appealing for rapid deployment in research and clinical settings.

bioengineering↗

bioRxiv2024

Epigenetic Reprogramming of Autophagy Drives Mutant IDH1 Glioma Progression and Response to Radiation

Mutant isocitrate dehydrogenase 1 (mIDH1) exhibits a gain of function mutation enabling 2-hydroxyglutarate (2HG) production and epigenetic reprogramming. This leads to enhanced DNA-damage response and radioresistance in mIDH1 gliomas. RNA-seq and ChIP-seq data revealed that human and mouse mIDH1 glioma neurospheres have downregulated gene ontologies (GOs) related to mitochondrial metabolism and upregulated GOs related to autophagy. Decreased mitochondrial metabolism was accompanied by decreased glycolysis, rendering autophagy a source of energy in mIDH1 gliomas. Human and mouse mutant IDH1 glioma cells exhibited increased expression of pULK1-S555 and enhanced LC3 I/II conversion, indicating augmented autophagy. Additionally, scRNA-seq data from human mIDH1 astrocytoma patients samples showed decreased mitochondrial metabolism and increased autophagy. We further demonstrate that inhibiting autophagy in vivo by systemic administration of synthetic protein nanoparticles encapsulating siRNA targeting Atg7 sensitized mIDH1 glioma cells to radiation-induced cell death, resulting in tumor regression, long-term survival, and immunological memory. In summary, our work uncovered that autophagy is a critical pathway for survival in mIDH1 gliomas and by blocking this pathway we can elicit radiosensitivity in vitro in human and mouse mIDH1 glioma cells, and in vivo in genetically engineered mouse models. Our data also highlights that blocking autophagy has significant potential for clinical translation. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=102 SRC="FIGDIR/small/584091v2_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@111f4a9org.highwire.dtl.DTLVardef@1d5bb30org.highwire.dtl.DTLVardef@f467ecorg.highwire.dtl.DTLVardef@1d2e9b5_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical Abstract:C_FLOATNO Our genetically engineered mIDH1 mouse glioma model harbors IDH1R132H in the context of ATRX and TP53 knockdown. The production of 2-HG elicited an epigenetic reprogramming associated with a disruption in mitochondrial activity and an enhancement of autophagy in mIDH1 glioma cells. Autophagy is a mechanism involved in cell homeostasis related with cell survival under energetic stress and DNA damage protection. Autophagy has been associated with radio resistance. The inhibition of autophagy thus radio sensitizes mIDH1 glioma cells and enhances survival of mIDH1 glioma-bearing mice, representing a novel therapeutic target for this glioma subtype with potential applicability in combined clinical strategies. C_FIG

cancer biology↗

bioRxiv2024

The genomic and cultural diversity of the Inka Qhapaq hucha ceremony in Chile and Argentina

The South American archaeological record has ample evidence of the socio-cultural dynamism of human populations in the past. This has also been supported through the analysis of ancient genomes, by showing evidence of gene flow across the region. While the extent of these signals is yet to be tested, the growing number of ancient genomes allows for more fine-scaled hypotheses to be evaluated. In this study, we assessed the genetic diversity of individuals associated with the Inka ritual, Qhapaq hucha. As part of this ceremony, one or more individuals were buried with Inka and local-style offerings on mountain summits along the Andes, leaving a very distinctive record. Using paleogenomic tools, we analyzed three individuals: two newly-generated genomes from El Plomo Mountain (Chile) and El Toro Mountain (Argentina), and a previously published genome from Argentina (Aconcagua Mountain). Our results reveal a complex demographic scenario with each of the individuals showing different genetic affinities. Furthermore, while two individuals showed genetic similarities with present-day and ancient populations from the southern region of the Inka empire, the third individual may have undertaken long-distance movement. The genetic diversity we observed between individuals from similar cultural contexts supports the highly diverse strategies the Inka implemented while incorporating new territories. More broadly, this research contributes to our growing understanding of the population dynamics in the Andes by discussing the implications and temporality of population movements in the region.

genomics↗

bioRxiv2023

Can changes in ploidy drive the evolution to allogamy in a selfing species complex?

O_LIThe evolution of mating systems in plants is central for understanding the rise of their diversity on Earth. The transition towards self-fertilization is a well-known example of convergent evolution although the opposite direction is expected to be forbidden according to evolutionary theories. We suggest that the ploidy level could promote changes in the reproductive strategies through its effect on traits related to pollination. C_LIO_LIWe performed controlled crosses on several populations from the polyploid Erysimum incanum species complex, described as predominantly selfing, to evaluate the inbreeding depression. Additionally, we measured mating traits such as floral size, herkogamy, anther exertion, the relative investment in male and female components (P:O ratio) and genetic diversity. C_LIO_LIWe described three ploidy levels in the complex - hexaploids were unknown until now. We found significant differences in the self-pollination success among ploidies and even among populations within the same ploidy. Inbreeding depression was present in higher ploidies, accompanied by bigger flowers with higher anther exposure, increased herkogamy and P:O and genetic diversity. C_LIO_LIThese findings suggest that ploidy could be promoting alternative reproductive strategies to selfing, driving mating system diversification within a selfing species, which has not been previously described in the wild. C_LI

plant biology↗

bioRxiv2023

De novo lipogenesis pathway is a vulnerability in IDH1 mutant glioma

Histone deacetylases (HDACs) have a wide range of targets and can rewire both the chromatin and lipidome of cancer cells. In this study, we show that valproic acid (VPA), a brain penetrant anti-epileptic and histone deacetylase inhibitor, inhibits the growth of IDH1 mutant tumors in vivo and in vitro, with at least some selectivity over IDH1 wild type tumors. Surprisingly, genes upregulated by VPA showed no change in chromatin accessibility at the promoter, but there was a correlation between VPA downregulated genes and diminished promoter chromatin accessibility. VPA inhibited the transcription of lipogenic genes and these lipogenic genes showed significant decrease in promoter chromatin accessibility only in the IDH1 MT glioma cell lines tested. VPA targeted a key lipogenic gene, fatty acid synthase (FASN), via inhibition of the mTOR pathway and both VPA and a selective FASN inhibitor TVB-2640 rewired the lipidome and promoted apoptosis in an IDH1 MT but not in an IDH1 WT glioma cell line. We further find HDACs are involved in the regulation of lipogenic genes and in particular HDAC6 is important for regulation of FASN in IDH1 MT glioma. Finally, we show that FASN knockdown alone and VPA in combination with FASN knockdown significantly improved the survival of mice in a IDH1 MT primary orthotopic xenograft model in vivo. We conclude that targeting fatty acid metabolism through HDAC inhibition and/or FASN inhibition may be a novel therapeutic option in IDH1 mutant gliomas.

cancer biology↗

bioRxiv2023

PAH DEFICIENT PATHOLOGY IN HUMANIZED c.1066-11G>A PHENYLKETONURIA MICE

We have generated using CRISPR/Cas9 technology a partially humanized mouse model of the neurometabolic disease phenylketonuria (PKU), carrying the highly prevalent PAH variant c.1066-11G>A. This variant creates an alternative 3 splice site, leading to the inclusion of 9 nucleotides coding for 3 extra amino acids between Q355 and Y356 of the protein. Homozygous Pah c.1066-11A mice, with a partially humanized intron 10 sequence with the variant, accurately recapitulate the splicing defect and present almost undetectable hepatic PAH activity. They exhibit fur hypopigmentation, lower brain and body weight and reduced survival. Blood and brain phenylalanine levels are elevated, along with decreased tyrosine, tryptophan and monoamine neurotransmitter levels. They present behavioral deficits, mainly hypoactivity and diminished social interaction, locomotor deficiencies and an abnormal hind-limb clasping reflex. Changes in the morphology of glial cells, increased GFAP and Iba1 staining signals and decreased myelinization are observed. Hepatic tissue exhibits nearly absent PAH protein, reduced levels of chaperones DNAJC12 and HSP70 and increased autophagy markers LAMP1 and LC3BII, suggesting possible coaggregation of mutant PAH with chaperones and subsequent autophagy processing. This PKU mouse model with a prevalent human variant represents a useful tool for pathophysiology research and for novel therapies development.

pathology↗