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Vijay, V.

Publications and source records attributed to Vijay, V..

9 recordsLinked to original sources

Integrative Multi-Tissue Analysis Identifies Synaptic Gene Networks Specific to Major Depressive Disorder in Women

Major Depressive Disorder (MDD) shows marked gender differences in prevalence and molecular signatures. Transcriptomic studies of post-mortem human brain tissue have reported alterations in the expression of synapse-related genes in MDD, including gender-specific patterns. But it remains unclear whether transcriptional changes observed in the brains of women with MDD are detectable in peripheral blood and conserved in experimental stress models. Whole-blood RNA sequencing was performed in women with MDD (n = 6) and matched healthy controls (n = 4). Differentially expressed genes (DEGs) were compared with previously reported female-specific blood and post-mortem brain transcriptomic datasets where selected overlapping synapse-associated genes were evaluated in the hippocampus and prefrontal cortex of female mice exposed to Chronic Variable Mild Stress (CVMS). Peripheral blood analysis identified DEGs enriched for synaptic organization, neuronal structure, and ion transport pathways. A substantial proportion of DEGs overlapped with previously reported datasets from peripheral blood, female MDD brain transcriptomic studies, and genes showing exclusive/enriched expression in the normal human brain. Network-based prioritization identified seven synapse-associated genes (SHANK2, SHANK3, CACNG8, GPHN, PICK1, NRXN2 and DNM2) for further analysis. In the female CVMS model, several of these genes showed altered expression in the hippocampus and/or prefrontal cortex, alongside behavioural changes and reduced dendritic spine density. These findings highlight shared transcriptional signals across human blood and human brain datasets, as well as in the mouse brain. However, larger studies are required to confirm and validate these observations.

neuroscience↗

CARIBOU: Computational AI Research Interface for Bioinformatics, Omics, and Unifying Agents

The growing gap between biological data generation and the availability of expert analysts motivates the development of AI systems capable of autonomously performing meaningful computational biology workflows. Here, we present CARIBOU (Computational AI Research Interface for Bioinformatics, Omics, and Unifying Agents), a multi-agent framework designed for practical deployment within institutional research computing environments. CARIBOU organizes specialized AI agents through researcher-modifiable blueprints that encode analytical roles, domain knowledge, and workflow guidance. All analyses are executed within reproducible computational environments compatible with Singularity/Apptainer-based high-performance computing (HPC) systems commonly used in academic research, while maintaining a persistent shared analytical state across multiple stages of analysis. This design enables CARIBOU to iteratively execute, troubleshoot, and refine bioinformatics workflows rather than simply generate static code. We evaluate CARIBOU across unit-task benchmarks, a metadata reconstruction challenge spanning six public datasets, and two end-to-end single-cell RNA-seq analyses using Allen Brain Atlas hippocampus and Tabula Sapiens large intestine datasets, alongside qualitative case studies demonstrating adaptive reasoning during analysis execution. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=137 SRC="FIGDIR/small/727730v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@1028f08org.highwire.dtl.DTLVardef@fc975dorg.highwire.dtl.DTLVardef@1355b2corg.highwire.dtl.DTLVardef@1f4ca39_HPS_FORMAT_FIGEXP M_FIG C_FIG IN BRIEFModern single-cell and spatial omics studies generate datasets that are increasingly difficult to analyze manually, creating a growing bottleneck between data generation and biological discovery. CARIBOU is a multi-agent AI system designed to autonomously perform bioinformatics analyses within the high-performance computing environments used by research institutions. By combining specialized AI agents with persistent execution environments and built-in analytical workflows, CARIBOU can adaptively execute, troubleshoot, and document complex analyses while maintaining reproducibility and compatibility with real-world research infrastructure.

bioinformatics↗

PantheonOS: An Evolvable Multi-Agent Framework for Automatic Genomics Discovery

The convergence of large language model-powered autonomous agent systems and single-cell biology promises a paradigm shift in biomedical discovery. However, existing biological agent systems, building upon single-agent architectures, are narrowly specialized or overly general, limiting applications to routine analyses. We introduce PantheonOS (https://PantheonOS.stanford.edu), an evolvable, privacy-preserving multi-agent framework designed to reconcile generality with domain specificity. Critically, PantheonOS enables agentic code evolution, allowing evolving state-of-the-art batch correction and our reinforcement-learning augmented gene panel selection algorithms to achieve super-human performance. PantheonOS drives biological discoveries across systems: uncovering asymmetric paracrine Cer1-Nodal inhibition in proximal-distal axis formation of novel early mouse embryo 3D data; integrating human fetal heart multi-omics with whole-heart data to reveal molecular programs underpin heart diseases; and adaptively selecting virtual cell models to predict cardiac regulatory and perturbation effects. Together, PantheonOS points towards a future where scientific discoveries are increasingly driven by self-evolving AI systems across biology and beyond. Websitehttps://pantheonos.stanford.edu Ecosystemhttps://github.com/aristoteleo SummaryLarge language model-powered agent systems are driving a paradigm shift in scientific discovery by automating, scaling, and accelerating data analysis. This transformation is particularly profound in biology, where the rapid expansion of single-cell and spatial genomics has effectively reshaped the field into a data-intensive science. However, existing biological agent systems are typically constrained to single-agent designs, are narrowly specialized, or are overly general without sufficient domain expertise, limiting their applicability to routine or shallow analyses. Here, we introduce PantheonOS (https://pantheonos.stanford.edu), an evolvable, privacy-preserving, and general-purpose multi-agent framework designed to reconcile generality with deep domain specificity. PantheonOS provides an abstract, extensible architecture that enables customized agent composition and supports end-to-end single-cell and multi-omics analysis, spanning reinforcement-learning-augmented gene panel design, raw FASTQ processing, multimodal data integration, and three-dimensional spatial genomics reconstruction. Central to this framework, Pantheon-Evolve enables agentic code evolution, allowing the system to autonomously improve state-of-the-art batch-correction algorithms and new reinforcement-learning based gene panel design algorithms, achieving performance beyond manually designed baselines. We demonstrate the power of PantheonOS across multiple biological domains. In early mouse embryogenesis, PantheonOS automatically reconstructs three-dimensional spatial gene expression landscapes and resolves asymmetric Cer1 expression and paracrine Cer1-Nodal inhibition, revealing a robust proximal-distal axis at embryonic day six (E6.0). In human development, PantheonOS integrates fetal heart single-cell multi-omics with whole-heart 3D MERFISH+ data at post-conception week 12, uncovering spatially resolved molecular programs underlying heart disease ontogeny. Finally, an intelligent model-routing mechanism enables PantheonOS to adaptively select optimal virtual cell models across heterogeneous tasks, revealing minimal regulatory networks of cardiogenesis and predicting spatially resolved perturbation effects in the developing heart. Together, PantheonOS establishes a foundation for fully automated, evolvable, and domain-aware agentic analysis in genomics, and points toward a future in which scientific discovery is increasingly driven by self-improving AI systems across biology and beyond.

bioinformatics↗

Reproducible generation of Nipah virus pseudovirions with uniform expression of F and G surface glycoproteins for high-throughput neutralization assays

Nipah virus (NiV) is a pathogen to be handled in BSL-4 facilities. Multiple surrogate systems such as virus-like particles (VLPs) and pseudoviruses enable carrying out NiV neutralization assays and study of virus entry pathways in biosafety level-2 (BSL-2) facilities. These are dual protein expression and surface display systems comprising NiV structural glycoproteins F and G as the key components. During generation of NiV VLPs or pseudovirions, ensuring batch to batch uniformity is a major concern due to the lack of proportionate expression of these proteins in the producer cells as well as their consistent incorporation in the particles. We established HEK293 pseudovirion producer cells that stably co-express NiV F and G proteins to address the issue. Fluorescence-activated cell sorting (FACS) analysis of clonally selected cells for high and uniform level F and G protein co-expression; and their further expansion were carried out to further refine the system. High titer vesicular stomatitis virus (VSV)-based pseudoviruses which showed consistent expression of both the glycoprotein were reproducibly generated from these producer cells. In functional assays, these pseudovirions exhibited a dose-dependent neutralization by commercial anti-NiV F and G antibodies as well as by convalescent serum from Nipah recovered patients. A pseudovirus neutralization test (PVNT) with a secreted alkaline phosphatase (SEAP) as the reporter was established in the study. The assay supports high-throughput adaptability with a quick turn-around time. It will aid large-scale human and animal serosurveillance studies in Nipah endemic regions as well as screening of virus entry inhibitors and monoclonal antibodies.

microbiology↗

Generation of a biliary tract cancer cell line atlas reveals molecular subtypes and therapeutic targets

Biliary tract cancers (BTCs) are a group of deadly malignancies encompassing intrahepatic and extrahepatic cholangiocarcinoma, gallbladder carcinoma, and ampullary carcinoma. Here, we present the integrative analysis of 63 BTC cell lines via multi-omics clustering and genome- scale CRISPR screens, providing a platform to illuminate BTC biology and inform therapeutic development. We identify dependencies broadly enriched in BTC compared to other cancers as well as dependencies selective to the anatomic subtypes. Notably, cholangiocarcinoma cell lines are stratified into distinct lineage subtypes based on biliary or dual biliary/hepatocyte marker signatures, associated with dependency on specific lineage survival factors. Transcriptional analysis of patient specimens demonstrates the prognostic significance of these lineage subtypes. Additionally, we delineate strategies to enhance targeted therapies or to overcome resistance in cell lines with key driver gene mutations. Furthermore, clustering based on dependencies and proteomics data elucidates unexpected functional relationships, including a BTC subgroup with partial squamous differentiation. Thus, this cell line atlas reveals potential therapeutic targets in molecularly defined BTCs, unveils biologically distinct disease subtypes, and offers a vital resource for BTC research.

cancer biology↗

Heterogeneous Nuclear Ribonucleoprotein C is an Indispensable Target in Acute Myeloid Leukemia

Refractory disease is the greatest challenge in acute myeloid leukaemia (AML). Previously, we found vascular-associated AML cells as a source for refractory disease. In this study we use a bioassay of AML cells co-cultured on bone marrow-derived endothelial cells (BMECs) to screen 31 million compounds within a mixture-based synthetic combinatorial library followed by deconvolution leading to the identification of a novel polyamine sulfonamide that is selectively toxic to AML. Using three distinct proteomics methods we identified heterogeneous nuclear ribonucleoprotein C (HNRNPC) as the compound target. Depleting HNRNPC reduces AML cell proliferation, viability, colony formation and fails to establish AML in mice. In contrast, no changes in cell proliferation, survival, or colony outgrowth were observed when depleting HNRNPC in normal hematopoietic or stromal cells. Clinical data show that lower HNRNPC expression independently associates with prolonged survival times in 554 adult and pediatric AML patients. We show that HNRNPC regulates DNA replication initiation and the Myc transcriptional program. Using differential isoform expression and differential alternative splicing analyses, we show significant alternative splicing of MAX after HNRNPC depletion, resulting in MAX transcript isoforms that lack Myc-interacting domains, which we term non-activating MAX isoforms. These Myc-interacting domains are necessary for the obligate heterodimerization of Myc and Max and are critical for Myc transcriptional activation. We further analyzed the alternative splicing landscapes of 538 AML patients and 33 specimens from healthy individuals and show substantial alternative splicing of mRNA in AML patients despite the absence of splicing factor gene mutations. Moreover, we found significantly high expression of non-activating MAX isoforms in healthy individuals, while AML patients highly expressed fully functional MAX isoforms, suggesting that MAX splicing may serve an important functional role in AML. Together, these data show HNRNPC as an indispensable splicing repressor in AML that is necessary for supporting deregulated Myc-Max activity and suggest HNRNPC as a potential therapeutic target for AML.

cancer biology↗

Efficient self-organization of blastoids solely from mouse ESCs is facilitated by transient reactivation of 2C gene network

Human pluripotent stem cells (hPSCs) can self-organize into a blastocyst-like structure (blastoid) by virtue of their full developmental potential. The pluripotent mouse embryonic stem cells (mESC) are considered to lack this potential and hence can form blastoids only when combined with trophoblast stem cells. We performed a small molecule and cytokine screen to demonstrate that mESC have full potential to efficiently self-organize themselves into E-blastoids (ESC-blastoids). The morphology, cell lineages and the transcriptome of these blastoids resemble the mouse blastocyst. The E-blastoids undergo implantation and in utero development in mice. The transient reactivation of the 2C-gene network by retinoid signaling is essential for E-blastoid generation. GSK3{beta} activity is critical for retinoid signaling and consequent 2C gene network activation. Collectively, the mESC possess full developmental potential to generate blastoids similar to hPSCs and other mammals. The plasticity of PSCs to self-organize into blastoids is not exclusive to humans or larger mammals; rather, it could be a general feature shared by most mammals, including rodents.

developmental biology↗

NRF2 activation induces NADH-reductive stress providing a metabolic vulnerability in lung cancer

Multiple cancers regulate oxidative stress by activating the transcription factor NRF2 through mutation of its negative regulator KEAP1. NRF2 has been studied extensively in KEAP1-mutant cancers, however the role of this pathway in cancers with wildtype KEAP1 remains poorly understood. To answer this question, we induced NRF2 via pharmacological inactivation of KEAP1 in a panel of 50+ non-small lung cancer cell lines. Unexpectedly, marked decreases in viability were observed in >13% of the cell lines--an effect that was completely rescued by NRF2 ablation. Genome-wide and targeted CRISPR screens revealed that NRF2 induces NADH-reductive stress, through the upregulation of the NAD+-consuming enzyme ALDH3A1. Leveraging these findings, we show that cells treated with KEAP1 inhibitors or those with endogenous KEAP1 mutations are selectively vulnerable to Complex I inhibition, which impairs NADH oxidation capacity and potentiates reductive stress. Thus, we identify reductive stress as a metabolic vulnerability in NRF2-activated lung cancers.

molecular biology↗

Protist.guru: a comparative transcriptomics database for the protist kingdom

SummaryDuring the last few decades, the study of microbial ecology has been enabled by molecular and genomic data. DNA sequencing has revealed the surprising extent of microbial diversity and how microbial processes run global ecosystems. However, significant gaps in our understanding of the microbial world remain, and one example is that microbial eukaryotes, or protists, are still neglected. To address this gap, we used gene expression data from 15 distinct protist species to create protist.guru: an online database equipped with tools for identifying functional co-expression networks, gene families, and enriched gene clusters. Here, we show how our database can be used to reveal genes involved in essential pathways, such as the synthesis of secondary carotenoids in Haematococcus lacustris. We expect protist.guru to serve as a valuable resource for protistologists, as well as a catalyst for discoveries and new insights into the biological processes of microbial eukaryotes. AvailabilityThe database and co-expression networks are freely available from http://protist.guru/. The expression matrices and sample annotations are found in the supplementary data.

evolutionary biology↗