Biology subjects

Monteiro, L.

Publications and source records attributed to Monteiro, L..

5 recordsLinked to original sources

bioRxiv2026

VaLPAS: Leveraging variation in experimental multi-omics data to elucidate protein function

MotivationDespite continuing advances in sequencing and computational function determination, large parts of the studied gene, protein, and metabolite space remain functionally undetermined. Most function assignment is driven by homology searches and annotation transfer from known and extensively studied proteins but often fails to leverage available experimental omics data generated via technologies like mass-spectrometry. ResultsThe VaLPAS (Variation-Leveraged Phenomic Association Screen) framework is available as a Python package and provides a user-friendly platform for calculation of associations between expression patterns of genes or proteins in multi-omic datasets based on various statistical and learning methods. The goal of this approach is to shed light on the functional dark matter of protein space by elucidating previously unknown functions of molecules using guilt by association with molecules of known function. We present results demonstrating the utility of VaLPAS to identify high-confidence predictions for a subset of genes/proteins of unknown function in a previously published multi-omics dataset from the oleaginous yeast, Rhodotorula toruloides. AvailabilityVaLPAS is written in Python. The code is hosted on github (https://github.com/PNNL-Predictive-Phenomics/valpas/).

bioinformatics↗

bioRxiv2024

Morphometric Identification of Parvalbumin-Positive Interneurons: A Data-Driven Approach

Traditionally, anatomical studies of parvalbumin-positive (PV+) labelled interneurons describe them as a homogeneous population of neurons. In contrast, recent single-cell RNAseq studies have identified multiple transcriptomically distinct categories of PV+ cells. That difference between a single anatomical category of PV+ neurons and multiple transcriptomic categories presents a problem in understanding the role of these neurons in cortical function. One gap that might contribute to this discrepancy is that PV+ morphology is typically addressed using qualitative descriptions and simple quantifications, while single-cell RNAseq studies use big data and high dimensional analyses. PV+ neurons play critical roles in the experience-dependent development of the cortex and are often involved in disease-related changes associated with neurodegenerative and neuropsychiatric disorders. Here, we developed a modern data-driven analysis pipeline to quantify PV+ morphology. We quantified 97 morphometric features from 14274 PV+ neurons and applied unsupervised clustering that identified 13 different PV+ morphologies. We extended the analysis to compare PV+ dendritic arbour patterns and cell body morphologies. Finally, we compared the morphologies of PV+ neurons with the cell body morphologies of neurons expressing various genes associated with PV+ transcriptomic cell types. This approach identified a range of PV+ morphologies similar to the number of transcriptomic categories. It also found that the PV+ morphologies have cortical area, laminar, and transcriptomic biases that might contribute to cortical function.

neuroscience↗

bioRxiv2023

Sex-Specific Development of ssRNA Virus Receptor Gene Expression in the Human Brain

Neurotropic single-stranded RNA (ssRNA) viruses can disrupt brain function, yet little is known about how host virus receptor expression develops across the human lifespan or whether these trajectories differ between females and males. We focused on postnatal development using postmortem transcriptomic data from 33 human donors (4 months-82 years; both sexes), comprising 52 cerebral hemispheres and 15 brain areas, to characterize developmental patterns of 67 host receptor genes that mediate entry of major ssRNA viral families. Using sex-specific LOESS trajectory modelling, hierarchical clustering, and sliding-window differential expression analyses, we identified multiple non-linear developmental programs governing virus receptor expression. About half of female-male gene-area trajectory pairs exhibited divergent developmental patterns. Sex differences were most pronounced in the cortex, where high-dimensional receptor expression profiles were sufficient to predict the sex of individual cases. Sex differential expression was most frequent during early childhood, coinciding with sensitive periods of cortical circuit refinement. A targeted prenatal analysis revealed that virus receptor expression was predominantly male-biased before birth, contrasting with the predominantly female-biased expression observed during the early postnatal period. Although receptors from most viral families were broadly distributed across developmental programs, a subset of sex-by-age expression clusters showed some enrichment for specific viral lineages and glial-associated cell-type signatures. Together, these findings reveal that virus receptor expression in the human brain is organized into structured, sex-biased trajectories that dynamically reorganize over development, providing the first developmental atlas of viral entry receptors in the human brain. Significance StatementMany viruses that affect the brain use host receptors to enter cells, yet it is unclear how these receptors are expressed across the human lifespan or whether their expression differs between females and males. Using human postmortem brain transcriptomic data spanning infancy to older adulthood, we show that virus receptor genes follow dynamic, sex-biased developmental trajectories, particularly in the cortex. These patterns are strongest during early childhood and are sufficient to distinguish female and male expression profiles at the individual level. Rather than acting as static entry points, virus receptors are embedded within developmental and neuroimmune programs. These findings provide a developmental framework for understanding why vulnerability to neuroinfectious disease may vary by age, brain area, and sex.

neuroscience↗

bioRxiv2022

In macrophages fatty acid oxidation spares glutamate for use in diverse metabolic pathways required for alternative activation

Fatty acid oxidation (FAO) is upregulated in IL-4-stimulated (alternatively activated) macrophages (M(IL-4)). We examined the effect of loss of function of the enzyme Cpt1a, which facilitates the entry of long chain fatty acids (FA) into mitochondria for FAO, on alternative activation. Expression of M(IL-4) markers ARG1, CD301 and RELM, was impaired in tamoxifen-treated ERT2Cre x Cpt1afl/fl macrophages and in macrophages expressing shRNA targeting Cpt1a (Cpt1a-shRNA). In contrast, VaviCre x Cpt1afl/fl and LysmCre x Cpt1afl/fl M(IL-4) responded normally to IL-4. Reduced alternative activation due to Cpt1a loss of function was linked to decreased cellular pools of -ketoglutarate, glutamate, and glutathione, diminished commitment of glucose carbon to serine/glycine synthesis, and decreased expression of genes in the Nrf2-oxidative stress response pathway. Consistent with this, reactive oxygen species were increased. Restoration of glutathione pools with N-acetyl cysteine normalized oxidative stress and allowed alternative activation in the face of Cpt1a-deficiency, pointing to a role for FAO in the control of ROS and as being important for alternative activation. In VaviCre x Cpt1afl/fl M(IL-4), glutamine uptake was increased, compensating for the loss of FAO to meet necessary metabolic demands, to allow alternative activation. The data indicate that macrophages are able to regulate glutamine metabolism to compensate for chronic disruption of FAO to meet metabolic needs.

immunology↗

bioRxiv2021

Gas6 drives Zika virus-induced neurological complications in humans and congenital syndrome in immunocompetent mice

Zika virus (ZIKV) has the ability to cross placental and brain barriers, causing congenital malformations in neonates and neurological disorders in adults. However, the pathogenic mechanisms of ZIKV-induced neurological complications in adults and congenital malformations remain unknown. Gas6 is a soluble TAM receptor ligand able to promote flavivirus internalization and downregulation of immune responses. Here we demonstrate high Gas6 levels in the serum of patients with neurological complications which correlated with downregulation of genes associated with the type I IFN responses as consequence of Socs1 upregulation. Gas6 gamma-carboxylation is essential for ZIKV replication in monocytes, the main source of this protein. Gas6 also facilitates ZIKV replication in adult immunocompetent mice enabled susceptibility to transplacental infection and congenital malformations. Our data thus indicate that ZIKV promotes the upregulation of its ligand Gas6, which contributes to viral infectivity and drives the development of severe adverse outcomes during ZIKV infection.

microbiology↗