Biology subjects

Diaz, C.

Publications and source records attributed to Diaz, C..

11 recordsLinked to original sources

bioRxiv2026

Spatiotemporal distribution of Delta-like protein 1 during mouse pituitary ontogeny and its relationship with differentiating endocrine cell populations

Delta-like protein 1 (DLK1) is a transmembrane protein involved in the regulation of cellular differentiation and stem cell maintenance in several tissues, including the pituitary gland. Although DLK1 expression has been reported in the adult pituitary, its spatiotemporal distribution during mouse pituitary development remains incompletely characterized. The aim of this study was to analyse the distribution of DLK1 during embryonic and postnatal development of the mouse pituitary gland and to characterize its relationship with hormone-producing cell populations. Immunohistochemistry was performed in Swiss albino mice from embryonic day 9.5 (e9.5) to postnatal day 15 (p15). Double immunofluorescence was used at e18.5 and p15 to examine the association of DLK1 immunoreactivity with ACTH-, TSH-, GH-, FSH- and PRL-producing cells. DLK1 immunoreactivity was detected from the earliest stages of pituitary development in Rathke's pouch and the ventral diencephalon. During embryonic development, DLK1-ir cells were widely distributed throughout adenohypophyseal and neurohypophyseal primordia. As development progressed, DLK1 immunoreactivity became progressively regionalized within the anterior, intermediate and tuberal lobes, as well as in the median eminence of the hypothalamus and the posterior pituitary lobe. Cells displaying overlapping immunoreactivity for DLK1 and all hormone-producing cell populations analysed were observed at e18.5 and p15. Semiquantitative analysis at p15 indicated that approximately 32% of adenohypophyseal cells were DLK1-immunoreactive. These findings provide a detailed description of the spatiotemporal distribution of DLK1 during mouse pituitary ontogeny and suggest that DLK1 immunoreactivity is associated with differentiating endocrine cell populations throughout pituitary development.

Developmental Biology↗

bioRxiv2026

Subcortical recruitment dissociates isoflurane emergence from distinct wakeful states in mice

Emergence from general anesthesia, defined by a recovery of consciousness to the wakeful state, is a clinically consequential state transition that remains a passive process dependent on drug clearance. Despite the critical use of anesthesia, the neural circuitry underlying behavioral recovery remains poorly defined. Here, we map whole-brain neural activity during emergence from isoflurane anesthesia in mice using Fos immunolabeling, tissue clearing, and light-sheet microscopy. This approach enables unbiased quantification of neural activity at cellular resolution across the intact whole brain and supports subsequent network analysis. Rather than resembling wakefulness, emergence exhibits widespread cortical suppression alongside selective activation of discrete subcortical nuclei. This pattern of activity includes both previously implicated arousal-related regions and lesser-studied structures linked to respiratory, autonomic, interoceptive, and cerebellar function. By comparing emergence to two behaviorally distinct wakeful control states, we find that control state selection substantially shapes interpretation of whole-brain activity maps. This establishes dual-state comparisons as a broadly useful strategy for state-dependent circuit mapping. Functional network analysis further elucidates candidate central regions that strongly covary together during emergence, with the most integrated region being the ventral orbital cortex. This approach allows for targeted causal investigation, linking brain-wide circuit discovery with future hypothesis-driven mechanistic interrogation. Together, we find that emergence from isoflurane anesthesia reflects selective subcortical recruitment rather than broad global reactivation toward wakefulness. Significance StatementMillions of people undergo general anesthesia each year. While anesthetic unconsciousness is induced rapidly, emergence from altered consciousness is unpredictable. Neural mechanisms that underlie behavioral emergence remain poorly defined. Using whole-brain Fos mapping at cellular resolution, we found that emergence from isoflurane anesthesia is characterized by widespread cortical suppression alongside selective activation of discrete subcortical, autonomic, hindbrain, and cerebellar nuclei. This selective systems-level activity pattern identifies behavioral emergence as more than a simple global return toward wakefulness and highlights underappreciated neural circuitry involved in post-anesthetic recovery. Network analysis of the Fos maps further identifies candidate regions for targeted causal investigation of emergence-related regions.

neuroscience↗

bioRxiv2025

Anti-Biofouling Albumin Amyloid Coatings Enable Vancomycin-Mediated Bacterial Eradication on Medical Tubing.

Indwelling medical devices such as catheters and endotracheal tubes are major drivers of hospital-acquired morbidity and mortality due to bacterial colonization. The resulting healthcare-associated infections (HAIs) are further exacerbated by rising antimicrobial resistance, underscoring the urgent need for strategies that both prevent biofilm formation and reduce reliance on antibiotics. Polyvinyl chloride (PVC), a widely used material in medical tubing, is highly prone to bacterial attachment, making it a critical target for intervention. Here, we show that complete eradication of Staphylococcus aureus--both sessile on PVC and planktonic--can be achieved using a bovine serum albumin (BSA) amyloid-like coating in combination with vancomycin at a dose eight times lower than the MIC. While the amyloid film alone markedly reduces bacterial adhesion, the residual bacterial load still reaches infection-risk thresholds. This dual approach therefore not only prevents biofilm development but also significantly lowers antibiotic requirements, reducing the risk of resistance emergence and improving therapeutic safety. The coatings, deposited on PVC and on glass (as a model surface), were synthesized using dithiothreitol (DTT) as a reducing agent, as alternative to tris(2-carboxyethyl)phosphine (TCEP). Through optimization of the synthesis, the resulting films preserved their physicochemical and anti-biofouling properties while offering a simple, low-cost, and scalable approach. The coatings strongly adhere to both substrates, remain stable under aqueous and mechanical stress, and effectively suppress bacterial and mammalian cell adhesion without cytotoxicity. These properties are clinically relevant, reducing infection risk and mitigating tubing failure due to fibrous capsule formation, encasement, or crystallized biofilm-induced blockage. The demonstrated biocompatibility, robustness, and scalability of this coating platform underscore its translational potential as a clinically relevant strategy to mitigate HAIs, extend the functional lifetime of medical tubing, and alleviate the global burden of antimicrobial resistance.

bioengineering↗

bioRxiv2025

New insights into the metabolomic signatures of spontaneously hypertensive rats

BACKGROUNDHypertension is a major risk factor associated with cardiovascular diseases and one of the leading causes of premature death. Hypertension has no obvious clinical signs; therefore, the identification of new biomarkers for the early detection of people at risk is needed to prevent hypertension and its further complications. Metabolomics is a useful tool for studying in vivo metabolic profiles that better understand the pathogenesis of diseases such as hypertension. This work aimed to explore the plasma and urinary non-targeted metabolic profile of 16-week-old spontaneously hypertensive rats (SHR) to identify new metabolomic profiles associated with hypertensive phenotypical characteristics that allow early diagnosis of patients at risk. METHODSPlasma and 24-hours urine samples were collected from 10 SHR and 10 age-matched normotensive Wistar-Kyoto 16-week-old male rats. Plasma and urinary metabolic profiles were investigated using high-performance liquid chromatography quadrupole time of flight coupled to mass spectroscopy followed by multivariate statistical analysis. The mummichog pathway enrichment analysis was used to integrate metabolomics data into biological contexts. RESULTSA total of 16 differential metabolites were found in plasma and 13 differential metabolites in urine from SHR compared to normotensive rats. Differences in some microbiota-derived metabolites suggest changes in the gut microbiota associated with hypertension in our experimental model. The mummichog algorithm has recognized that hypertensive metabolism is associated with the altered metabolism of steroid hormones, bile acid and purines. CONCLUSIONSThis work highlights the importance of metabolomics as a tool for the identification of biomarkers in the early detection of hypertension, a condition that represents a significant risk to cardiovascular health. The findings suggest that hypertension is associated with alterations in the metabolism of steroid hormones, bile acids and purines, as well as metabolites derived from the intestinal microbiota. These results not only contribute to a better understanding of the pathogenesis of hypertension but also open the door to future research in humans that could facilitate more accurate and earlier diagnoses, thus helping to prevent serious complications associated with this disease.

biochemistry↗

bioRxiv2023

A genome-wide atlas of human cell morphology

A key challenge of the modern genomics era is developing data-driven representations of gene function. Here, we present the first unbiased morphology-based genome-wide perturbation atlas in human cells, containing three genome-scale genotype-phenotype maps comprising >20,000 single-gene CRISPR-Cas9-based knockout experiments in >30 million cells. Our optical pooled cell profiling approach (PERISCOPE) combines a de-stainable high-dimensional phenotyping panel (based on Cell Painting1,2) with optical sequencing of molecular barcodes and a scalable open-source analysis pipeline to facilitate massively parallel screening of pooled perturbation libraries. This approach provides high-dimensional phenotypic profiles of individual cells, while simultaneously enabling interrogation of subcellular processes. Our atlas reconstructs known pathways and protein-protein interaction networks, identifies culture media-specific responses to gene knockout, and clusters thousands of human genes by phenotypic similarity. Using this atlas, we identify the poorly-characterized disease-associated transmembrane protein TMEM251/LYSET as a Golgi-resident protein essential for mannose-6-phosphate-dependent trafficking of lysosomal enzymes, showing the power of these representations. In sum, our atlas and screening technology represent a rich and accessible resource for connecting genes to cellular functions at scale.

genomics↗

bioRxiv2023

Phylomitogenomics bolsters the high-level classification of Demospongiae (phylum Porifera)

Class Demospongiae - the largest in the phylum Porifera (Sponges) - encompasses nearly 8,000 accepted species in three subclasses: Keratosa, Verongimorpha, and Heteroscleromorpha. Subclass Heteroscleromorpha contains [~]90% of demosponge species and is subdivided into 17 orders. The higher level classification of demosponges underwent major revision as the result of nearly three decades of molecular studies. However, because most of the previous molecular work only utilized partial data from a small number of nuclear and mitochondrial (mt) genes, this classification scheme needs to be tested by larger datasets. Here we compiled a mt dataset for 136 demosponge species - including 64 complete or nearly complete and six partial mt-genome sequences determined or assembled for this study - and used it to test phylogenetic relationships among Demospongiae in general and Heteroscleromorpha in particular. We also investigated the phylogenetic position of Myceliospongia araneosa - a highly unusual demosponge without spicules and spongin fibers, currently classified as Demospongiae incertae sedis, for which molecular data were not available. Our results support the previously inferred sister-group relationship between Heteroscleromorpha and Keratosa + Verongimorpha and suggest five main clades within Heteroscleromorpha: Clade C0 composed of order Haplosclerida; Clade C1 composed of Scopalinida, Sphaerocladina, and Spongillida; Clade C2 composed of Axinellida, Biemnida, Bubarida; Clade C3 composed of Tetractinellida; and Clade C4 composed of Agelasida, Clionaida, Desmacellida, Merliida, Suberitida, Poecilosclerida, Polymastiida, and Tethyida. The inferred relationships among these clades were (C0(C1(C2(C3+C4)))). Analysis of molecular data from M. araneosa placed it in the C3 clade as a sister taxon to the highly skeletonized tetractinellids Microscleroderma sp. and Leiodermatium sp. Molecular clock analysis dated divergences among the major clades in Heteroscleromorpha from the Cambrian to the Early Silurian, the origins of most heteroscleromorph orders in the middle Paleozoic, and the most basal splits within these orders around the Paleozoic to Mesozoic transition. Overall, the results of this study are mostly congruent with the accepted classification of Heteroscleromorpha, but add temporal perspective and new resolution to phylogenetic relationships within this subclass.

evolutionary biology↗

bioRxiv2021

Identification of the 216kbp gene cluster and structure elucidation of gargantulides B and C, new complex 52-membered macrolides from Amycolatopsis sp.

Gargantulides B and C, two new and highly complex 52-membered glycosylated macrolactones, were isolated from Amycolatopsis sp. strain CA-230715 during an antibacterial screening campaign. The structures of these giant macrolides were elucidated by 2D NMR spectroscopy and shown to be related to gargantulide A, although containing additional {beta}-glucopyranose and/or -arabinofuranose monosaccharides separately attached to their backbones. Genome sequencing allowed the identification of a strikingly large 216 kbp biosynthetic gene cluster, among the largest type I PKS clusters described so far, and the proposal of a biosynthetic pathway for gargantulides A-C. Additionally, genes putatively responsible for the biosynthesis of the amino sugar {beta}-3,6-deoxy-3-methylamino glucose, reported exclusively in gargantulide macrolides, were also found in the cluster and described in this work. The absolute configurations of gargantulides B and C were assigned based on a combination of NMR and bioinformatics analysis of ketoreductase and enoylreductase domains within the multimodular type I PKS. Furthermore, the absolute stereochemistry of the related macrolide gargantulide A has now been revised and completed. Gargantulides B and C display potent antibacterial activity against a set of drug-resistant Gram-positive bacteria and moderate activity against the clinically relevant Gram-negative pathogen Acinetobacter baumannii.

microbiology↗

bioRxiv2021

High efficacy of therapeutic equine hyperimmune antibodies against SARS CoV-2 variants of concern

SARS-CoV-2 variants of concern (VoC) show reduced neutralization by vaccine-induced and therapeutic monoclonal antibodies. We tested therapeutic equine polyclonal antibodies (pAbs) against four VoC (alpha, beta, epsilon and gamma). We show that equine pAbs efficiently neutralize VoC, suggesting they are an effective, broad coverage, low-cost and a scalable COVID-19 treatment.

microbiology↗

bioRxiv2020

Massively parallel phenotyping of variant impact in cancer with Perturb-seq reveals a shift in the spectrum of cell states induced by somatic mutations

Genome sequencing studies have identified millions of somatic variants in cancer, but their phenotypic impact remains challenging to predict. Current experimental approaches to distinguish between functionally impactful and neutral variants require customized phenotypic assays that often report on average effects, and are not easily scaled. Here, we develop a generalizable, high-dimensional, and scalable approach to functionally assess variant impact in single cells by pooled Perturb-seq. Specifically, we assessed the impact of 200 TP53 and KRAS variants in >300,000 single lung cancer cells, and used the profiles to categorize variants into phenotypic subsets to distinguish gain-of-function, loss-of-function and dominant negative variants, which we validated by comparison to orthogonal assays. Surprisingly, KRAS variants did not merely fit into discrete functional categories, but rather spanned a continuum of gain-of-function phenotypes driven by quantitative shifts in cell composition at the single cell level. We further discovered novel gain-of-function KRAS variants whose impact could not have been predicted solely by their occurrence in patient samples. Our work provides a scalable, gene-agnostic method for coding variant impact phenotyping, which can be applied in cancer and other diseases driven by somatic or germline coding mutations.

genomics↗

bioRxiv2020

Development and pre-clinical characterization of two therapeutic equine formulations towards SARS-CoV-2 proteins for the potential treatment of COVID-19

In the current global emergency due to SARS-CoV-2 outbreak, passive immunotherapy emerges as a promising treatment for COVID-19. Among animal-derived products, equine formulations are still the cornerstone therapy for treating envenomations due to animal bites and stings. Therefore, drawing upon decades of experience in manufacturing snake antivenom, we developed and preclinically evaluated two anti-SARS-CoV-2 polyclonal equine formulations as potential alternative therapy for COVID-19. We immunized two groups of horses with either S1 (anti-S1) or a mixture of S1, N, and SEM mosaic (anti-Mix) viral recombinant proteins. Horses reached a maximum anti-viral antibody level at 7 weeks following priming, and showed no major adverse acute or chronic clinical alterations. Two whole-IgG formulations were prepared via hyperimmune plasma precipitation with caprylic acid and then formulated for parenteral use. Both preparations had similar physicochemical and microbiological quality and showed ELISA immunoreactivity towards S1 protein and the receptor binding domain (RBD). The anti-Mix formulation also presented immunoreactivity against N protein. Due to high anti-S1 and anti-RBD antibody content, final products exhibited high in vitro neutralizing capacity of SARS-CoV-2 infection, 80 times higher than a pool of human convalescent plasma. Pre-clinical quality profiles were similar among both products, but clinical efficacy and safety must be tested in clinical trials. The technological strategy we describe here can be adapted by other producers, particularly in low- and middle-income countries.

microbiology↗

bioRxiv2017

A Comprehensive Reanalysis Of Publicly Available GWAS Datasets Reveals An X Chromosome Rare Regulatory Variant Associated With High Risk For Type 2 Diabetes.

The reanalysis of publicly available GWAS data represents a powerful and cost-effective opportunity to gain insights into the genetics and pathophysiology of complex diseases. We demonstrate this by gathering and reanalyzing public type 2 diabetes (T2D) GWAS data for 70,127 subjects, using an innovative imputation and association strategy based on multiple reference panels (1000G and UK10K). This approach led us replicate and fine map 50 known T2D loci, and identify seven novel associated regions: five driven by common variants in or near LYPLAL1, NEUROG3, CAMKK2, ABO and GIP genes; one by a low frequency variant near EHMT2; and one driven by a rare variant in chromosome Xq23, associated with a 2.7-fold increased risk for T2D in males, and located within an active enhancer associated with the expression of Angiotensin II Receptor type 2 gene (AGTR2), a known modulator of insulin sensitivity. We further show that the risk T allele reduces binding of a nuclear protein, resulting in increased enhancer activity in muscle cells. Beyond providing novel insights into the genetics and pathophysiology of T2D, these results also underscore the value of reanalyzing publicly available data using novel analytical approaches.

genetics↗