Biology subjects

Blanco, G.

Publications and source records attributed to Blanco, G..

9 recordsLinked to original sources

bioRxiv2026

Diet-dependent effects of kombucha on the gut microbiome and its neuroactive potential: Associations with reduced anxiety and depressive-like behaviors in mice

Fermented foods are increasingly recognized for their health-boosting potential, yet the mechanisms involved are not fully resolved. Here, we tested whether kombucha reshapes the gastrointestinal microbiome and whether these changes are associated with stress-related behaviors under contrasting dietary backgrounds. Male C57BL/6 mice were fed either a total Western diet (TWD) or a control diet (CTRL) supplemented with kombucha or water three times weekly for seven weeks. Depressive-like and anxiety-related behaviors were evaluated using the forced swimming (FST) and marble burying tests (MBT). Ileum, cecum, and colon microbiomes were profiled via 16S rRNA, ITS2, and shotgun metagenomics, while feces and whole brains were profiled by LC-MS metabolomics. Serum cytokines were measured by ELISA. Results highlight diet-dependent effects of Kombucha on behavioral, microbial and metabolic outcomes. Kombucha reduced immobility in the FST under both diets, whereas fewer marbles buried were observed only under TWD. Kombucha intake enriched Bifidobacterium pseudolongum in the ileum under CTRL and TWD diets, while cecal microbial functions related to amino acid metabolism were stimulated mainly under CTRL. Only CTRL mice receiving kombucha showed higher fecal acetate and butyrate together with lower fecal levels of neurochemically relevant amino acids, including glutamine, phenylalanine, tryptophan, and tyrosine. Under TWD, kombucha was associated with lower spleen weight and altered brain tryptophan/kynurenine profiles. These findings identify kombucha as a food intervention that can remodel gastrointestinal microbial and neuroactive metabolism in a diet depending manner. Associations with reduced depressive and anxiety-related behaviors are promising but warrant further exploration. Key HighlightsO_LIKombucha supplementation reshaped the mice gastrointestinal microbiome and its neuroactive potential C_LIO_LIKombucha intake was associated reduced depressive and anxious like behaviors C_LIO_LIThe potential of kombucha to modulate microbial, metabolic and behavioral outcomes may be dependent on subject dietary background C_LI

microbiology↗

bioRxiv2026

Natural variation in male frequency fails to predict inbreeding responses in Caenorhabditis elegans

In androdioecious species like Caenorhabditis elegans, where the primary mode of reproduction is self-fertilization, the evolutionary role of males has long puzzled biologists. One proposed benefit of males is the potential to escape inbreeding depression. We tested this by enforcing seven generations of inbreeding across nine C. elegans strains differing in baseline male frequency and measuring competitive relative fitness before and after inbreeding. We then relaxed inbreeding for four generations to assess recovery. We predicted that strains with higher male frequency, and greater opportunity for outcrossing, would exhibit faster recovery once inbreeding was relaxed. Strains varied substantially in their responses with most showing significant fitness declines and partial recovery but neither the magnitude of inbreeding depression nor the extent of recovery correlated with male frequency. These results show that male frequency is a poor predictor of inbreeding responses and does not reliably reflect realized outcrossing or its fitness consequences.

evolutionary biology↗

bioRxiv2025

Outcrossing Complicates Mutation Purging by Trapping Single Nucleotide Polymorphisms in Structural Variant Mutations

Classical mutational theories centered on single nucleotide polymorphisms suggest that outcrossing enhances the purging of deleterious mutations by promoting recombination. However, larger structural variants, such as insertions, deletions, and inversions, can suppress recombination and create linkage blocks. Using experimental evolution and whole-genome long- and short-read sequencing, we characterized structural and nucleotide mutation landscapes in three Caenorhabditis elegans strains following repeated mutagen exposure and recovery. We found substantial strain-specific differences in structural variant accumulation and mutation retention. The strain with the highest outcrossing propensity exhibited the greatest structural variant burden and a higher fraction of single nucleotide polymorphisms within structural variant intervals. Consistent with this pattern, our population genetic simulations showed that structural variants can persist more readily under higher outcrossing rates. Together, these results indicate that structural variant architecture may influence mutation retention dynamics and highlight strain-specific constraints on purging following mutagenesis in C. elegans.

bioinformatics↗

bioRxiv2025

Discovery of a VHL molecular glue degrader of GEMIN3 by Picowell RNA-seq

Targeted protein degradation (TPD) is an emerging therapeutic modality in which small molecules are used to recruit targets to the natural protein degradation machinery of the cell. Molecular glue degraders (MGD) are monovalent small molecules that accomplish this by redirecting E3 ubiquitin ligases to target proteins, offering the potential to degrade previously unliganded and "undruggable" proteins in cancer, neurodegenerative, and other diseases. While attractive due to their drug-like properties, MGDs are exceptionally hard to discover and have largely been identified serendipitously. The Von Hippel-Lindau (VHL) E3 ligase is the second most widely used effector for TPD, though current VHL-based degraders are primarily large heterobifunctional PROTACs (proteolysis-targeting chimeras) designed using target-based ligands. Here, we have instead pursued target-agnostic discovery of VHL MGDs leveraging proprietary ultra-miniaturized microfluidics devices (Picowells) to facilitate unbiased RNA-seq screening of a biased E3-focused library. This resulted in dGEM3, a novel VHL molecular glue that targets the survival of motor neuron (SMN) complex member GEMIN3 for degradation. Through a combination of cellular, biochemical, and biophysical assays, we have characterized the GEMIN3 degron within its helicase ATP-binding domain, and how the kinetics of ternary complex formation impact degradation. These findings provide insights on the re-programmability of VHL for novel targets using drug-like molecular glues.

biochemistry↗

bioRxiv2025

The sperm specific Na+,K+-ATPase α4 shows a highly structured and dynamic distribution at the sperm flagellum

Na+,K+-ATPase 4 is a unique cell plasma membrane Na+ and K+ transporter of spermatozoa, which is essential for male fertility. Previous studies have shown that Na+,K+-ATPase 4 is highly expressed in the sperm flagellum; however, the spatial arrangement of Na+,K+-ATPase 4 at the subcellular level and its relationship to the functional state of the cells are unknown. We studied this here using stimulated emission depletion (STED) super-resolution microscopy. We show that, under non-capacitated conditions, Na+,K+-ATPase 4 is distributed in a trilinear pattern along the midpiece and as a scattered single line along the principal piece segment of the sperm flagellum. Under capacitated conditions, Na+,K+-ATPase 4 pattern undergoes remodelling and its distribution shifts into a single line along the entire length of the flagellum. On the other hand, Na+,K+-ATPase 1 the somatic isoform of Na+,K+-ATPase also present in sperm, exhibits a similar trilaminar localization at the flagellar midpiece but a bilinear pattern in the principal piece. This distribution, unlike that of Na+,K+-ATPase 4, does not change during sperm capacitation. These differences in the localization pattern and spatial dynamics of Na+,K+- ATPase isoform expression highlights the dissimilarities in the roles of both ion transporters. The specific modulation of Na+,K+-ATPase 4 distribution, combined with the unique role that it has in sperm function, stresses the importance of Na+,K+-ATPase 4 for male fertility. Significance statementThis is the first demonstration of the highly structured nature of Na+,K+-ATPase in the plasma membrane of sperm, including the sperm specific Na+,K+-ATPase 4 isoform, which is key for male fertility, and the somatic Na+,K+-ATPase 1, which is present in all cells. Utilizing stimulated emission depletion (STED) super resolution microscopy, we discovered that Na+,K+- ATPase 4 and Na+,K+-ATPase 1 have different distributions along the sperm flagellum. Moreover, only Na+,K+-ATPase 4 undergoes remodelling during sperm capacitation. These specific patterns of localization that are dependent on the sperm functional state in combination with the different function and regulation of Na+,K+-ATPase isoforms highlights the sophisticated mechanisms that cells have evolved to fulfil their unique function.

cell biology↗

bioRxiv2023

Host space, not energy or symbiont size, constrains feather mite abundance across passerine bird species

Comprehending symbiont abundance among host species is a major ecological endeavour, and the metabolic theory of ecology has been proposed to understand what constraints symbiont populations. We parameterized metabolic theory equations to predict how bird species body size and the body size of their feather mites relate to mite abundance according to four potential energy (microbial abundance, uropygial gland size) and space constraints (wing area, number of feather barbs). Predictions were compared with the empirical scaling of feather mite abundance from 26,604 birds of 106 passerine species, using phylogenetic modelling and quantile regression. Feather mite populations were strongly constrained by host space (number of feather barbs) and not energy. Moreover, feather mite species body size was unrelated to their abundance or to the body size of their host species. We discuss the implications of our results for our understanding of the bird-feather mite system and for symbiont abundance in general.

ecology↗

bioRxiv2021

Buenos Aires, June 2021Inhibition of Mitochondrial Fission by Drp-1 Blockade by Short-Term Leptin and Mdvi-1 Treatment Improves White Adipose Tissue Abnormalities in Obesity and Diabetes

BackgroundObesity and type 2 diabetes are chronic diseases characterized by insulin resistance, mitochondrial dysfunction and morphology abnormalities. ObjectiveHerein, we investigated if dysregulation of mitochondrial dynamics and biogenesis is involved in an animal model of obesity and diabetes. MethodsThe effect of short-term leptin and mdivi-1 -a selective inhibitor of Drp-1 fission-protein- treatment on mitochondrial dynamics and biogenesis was evaluated in epididymal white adipose tissue (WAT) from male ob/ob mice. ResultsAn increase in Drp-1 protein levels and a decrease in Mfn2 and OPA-1 protein expression were observed with enhanced and sustained mitochondrial fragmentation in ob/ob mice compared to wt C57BL/6 animals (p<0.05). The content of mitochondrial DNA and mRNA expression of PGC-1 -both parameters of mitochondrial biogenesis- were reduced in ob/ob mice (p<0.05). Leptin and mdivi-1 treatment significantly increased mitochondrial biogenesis, improved fusion-to-fission balance and attenuated mitochondrial dysfunction, thus inducing white-to-beige adipocyte transdifferentiation. Measurements of glucose and lipid oxidation in adipocytes revealed that both leptin and mdivi-1 increase substrates oxidation while in vivo determination of blood glucose concentration showed decreased levels by 50% in ob/ob mice, almost to the wt level. ConclusionsPharmacological targeting of Drp-1 fission protein may be a potential novel therapeutic tool for obesity and type 2 diabetes.

molecular biology↗

bioRxiv2020

Remodeling of the core leads HIV-1 pre-integration complex in the nucleus of human lymphocytes.

Retroviral replication proceeds through obligate integration of the viral DNA into the host genome. To enter the nucleus, the viral DNA must be led through the nuclear pore complex (NPC). During HIV-1 cytoplasmic journey, the viral core acts like a shell to protect the viral genetic material from antiviral sensors and ensure an adequate environment for the reverse transcription. However, the relatively narrow size of the nuclear pore channel requires that the HIV-1 core reshapes into a structure that fits the pore. On the other hand, the organization of the viral CA proteins that remain associated to the pre-integration complex (PIC) during and after nuclear translocation, in particular, in human lymphocytes, the main target cells of HIV-1, is still enigmatic. In this study, we analysed the progressive organizational changes of viral CA proteins within the cytoplasm and the nucleus by immuno-gold labelling. Furthermore, we set up a novel technology, HIV-1 ANCHOR, which enables specific detection of the retrotranscribed DNA by fluorescence microscopy, thereby uncovering the architecture of the potential HIV-1 PIC. Thus, we revealed DNA- and CA-positive complexes by correlated light- and electron microscopy (CLEM). During and after nuclear translocation, HIV-1 appears as a complex of viral DNA decorated by multiple viral CA proteins remodelled in a "pearl necklace" shape. Thus, we observed how CA proteins reshape around the viral DNA to permit the entrance of the HIV-1 in the nucleus. This particular CA protein complex composed by the integrase and the retrotranscribed DNA leads HIV-1 genome inside the host nucleus to potentially replicate. Our findings contribute to the understanding of the early steps of HIV-1 infection and provide new insights into the organization of HIV-1 CA proteins during and after viral nuclear entry. ImportanceHow the reverse transcribed genome reaches the host nucleus remains a main open question related to the infectious cycle of HIV-1. HIV-1 core has a size of [~]100 nm, largely exceeding that of the NPC channel ([~]39 nm). Thus, a rearrangement of the viral CA proteins organization is required to achieve effective nuclear translocation. The mechanistic of this process remains undefined due to the lack of a technology capable to visualize potential CA sub-complexes in association with the viral DNA in the nucleus of HIV-1-infected cells. By the means of state-of-the-art technologies (HIV-1 ANCHOR system combined with CLEM), our study shows that remodeled viral complexes retain multiple CA proteins but not intact core or only a single CA monomer. These viral CA complexes associated with the retrotranscribed DNA can be observed in the outer and inner side of the NE, and they represent potential PIC. Thus, our study shed light on critical early steps characterizing HIV-1 infection, thereby revealing novel, therapeutically exploitable points of intervention. Furthermore, we developed and provided a powerful tool enabling direct, specific and high-resolution visualization of intracellular and intranuclear HIV-1 subviral structures.

microbiology↗

bioRxiv2018

Acute-stress impairs cytoprotective mechanisms through neural inhibition of the insulin pathway

Persistent activation of the \"fight-or-flight\" response accelerates aging and increases the susceptibility to disease. We show that repeated induction of the C. elegans flight response inhibits conserved cytoprotective mechanisms. This acute-stress response activates neurons that release tyramine, the invertebrate analog of adrenaline/noradrenaline. Tyramine stimulates the DAF-2/Insulin/IGF-1 pathway and precludes the nuclear translocation of the DAF-16/FOXO transcription factor through the activation of an adrenergic-like receptor TYRA-3 in the intestine. In contrast, environmental long-term stressors, such as heat or oxidative stress, reduce tyramine release allowing the induction of FOXO-dependent cytoprotective genes. These findings demonstrate how a neural stress-hormone signaling provides a state-dependent neural switch between acute and long-term stress responses, and provide mechanistic insights how acute stress impairs cellular defensive systems.\n\nOne Sentence Summary: The \"fight-or-flight\" response reduces resistance to environmental challenges.

neuroscience↗