Biology subjects

Ghosh, S.

Publications and source records attributed to Ghosh, S..

At least 127 records · Page 7Linked to original sources

bioRxiv2025

Synergistic RAS-MAPK and AKT Activation in MYC-Driven Tumors via Adjacent PVT1 Rearrangements

MYC-driven (MYC+) cancers are aggressive and often fatal. MYC dysregulation is a key event in these cancers, but overexpression of MYC alone is not always enough to cause cancer. Plasmocytoma Variant Translocation 1 (PVT1), a long non-coding RNA (lncRNA) adjacent to MYC on chromosome 8 is a rearrangement hotspot in many MYC+ cancers. In addition to being co-amplified with MYC, the genomic rearrangement at PVT1 involves translocation, which has had obscure functional consequences. We report that translocation at the PVT1 locus cause asymmetric enrichment of 5-PVT1 and loss of 3-PVT1. Despite being classified as a non-coding RNA, the retained 5 region of PVT1 generates a circular RNA (CircPVT1) that codes for the novel peptide we call Firefox (FFX). FFX augments AKT signaling and synergistically activates MYC and mTORC1 in these cells. Further, the 3 end of PVT1, which is lost during the translocation, codes for a tumor-suppressing micropeptide we named as Honeybadger (HNB). We demonstrate that HNB interacts with KRAS and disrupts the activation of KRAS effectors. Loss of HNB leads to activation of RAS/MAPK signaling pathway, and enhances MYC stability by promoting phosphorylation of MYC at Ser62. These findings identify PVT1 as a critical node that synchronizes MYC, AKT, and RAS-MAPK activities in cancer. Our study thus identifies a key mechanism by which rearrangements at the PVT1 locus activate additional oncogenic pathways that synergize with MYC to exacerbate the aggressiveness of MYC+ cancers. This newfound understanding explains the poor prognosis associated with MYC+ cancers and offers potential therapeutic targets that could be leveraged in treatment strategies for these cancers.

cancer biology↗

bioRxiv2025

AI-assisted protein design to rapidly convert antibody sequences to intrabodies targeting diverse peptides and histone modifications

Intrabodies are engineered antibodies that function inside living cells, enabling therapeutic, diagnostic, and imaging applications. While powerful, their development has been hindered by challenges associated with their folding, solubility, and stability in the reduced intracellular environment. Here, we present an AI-driven pipeline integrating AlphaFold2, ProteinMPNN, and live-cell screening to optimize antibody framework regions while preserving epitope-binding complementarity-determining regions. Using this approach, we successfully converted 19 out of 26 antibody sequences into functional single-chain variable fragment (scFv) intrabodies, including a panel targeting diverse histone modifications for real-time imaging of chromatin dynamics and gene regulation. Notably, 18 of these 19 sequences had failed to convert using the standard approach, demonstrating the unique effectiveness of our method. As antibody sequence databases expand, our method will accelerate intrabody design, making their development easier, more cost-effective, and broadly accessible for biological research.

cell biology↗

bioRxiv2025

A silicon rhodamine-fused glibenclamide to label and detect malaria-infected red blood cells

The malaria parasite Plasmodium falciparum affects the lives of millions of people worldwide every year. The detection of replicating parasites within human red blood cells is of paramount importance, requiring appropriate diagnostic tools. Herein, we design and apply a silicon rhodamine-fused glibenclamide (SiR-glib). We first test this far-red fluorescent, fluorogenic and endoplasmic reticulum-targeting sulfonylurea in mammalian cells and pancreatic tissues, before characterizing its labeling performance in red blood cells infected with the asexual developmental stages of Plasmodium falciparum. We further combine SiR-glib with a portable smartphone-based microscope to easily and rapidly identify parasitized red blood cells, providing proof of principle for diagnostic use in rural endemic areas without major healthcare facilities.

biochemistry↗

bioRxiv2025

BTK-NLRP3-Caspase1 and Gasdermin D-Caspase 11 pathways jointly drive neuroinflammation and functional impairments in a rat model of psychosocial stress

Despite serious health and economic burden, borne more prominently by lower and lower middle-income countries, pharmacotherapy for common psychiatric disorders rely on drugs altering neurotransmission, with partial efficacies. The persistence of a chronic yet sub-threshold inflammation across the periphery and the brain is well documented in the patients and animal models of these disorders and can be investigated for augmenting pharmacotherapy. IL1{beta}, a pleiotropic cytokine and a key regulator of neuroinflammation has been of particular interest in this regard. Previous studies on rodent models of anxiogenic stress show activation of a large multiprotein complex - the NLRP3 inflammasome, which increases IL1{beta} production facilitated by caspase 1, through what is considered a canonical inflammasome activation pathway. However, there exists a second non canonical inflammasome activation pathway whose impact on IL1{beta} release, inflammation and behavioral consequences remain unclear. Using rat models of physical and psychosocial stress, we observed stress-induced sex-specific upregulation of activated caspase 11 and gasdermin D N-terminal fragments, the mediators of the non-canonical inflammasome pathway that facilitates IL1{beta} release through pore formations in the plasma membrane. This is the first report of non-canonical inflammasome pathway being activated in the brain and peripheral immune cells in response to psychosocial stress. Inhibition of caspase 11 with wedelolactone, or Gasdermin D cleavage with Disulfiram reduced stress-induced elevation of IL1{beta} levels, anxiety and fear acquisition, facilitated fear extinction and recall, and improved working memory. Combination treatments targeting both canonical (ibrutinib for pBTK/NLRP3 or MCC950 for NLRP3 inhibition) and non-canonical (wedelolactone for caspase 11 or disulfiram for gasdermin D) pathways proved more efficacious in reducing stress-mediated neuroinflammation, dendritic spine elimination in the CA3 region of the hippocampus and behavioral dysfunction. Furthermore, psychosocial stress drove peripheral inflammation, in peripheral blood mononuclear cells, which was mitigated by the combination treatment. Taken together, this study reveals a novel mechanism underlying psychosocial stress involving both canonical and non-canonical inflammasome signaling to facilitate IL1{beta} induction and behavioral changes. Our finding further suggests that combined targeting of the NLRP3 inflammasome and gasdermin D could contribute to the development of future transdiagnostic therapeutic targets for stress, anxiety, and depression.

neuroscience↗

bioRxiv2025

TRAF6 integrates innate immune signals to regulate glucose homeostasis via Parkin-dependent and -independent mitophagy

Activation of innate immune signaling occurs during the progression of immunometabolic diseases, including type 2 diabetes (T2D), yet the impact of innate immune signaling on glucose homeostasis is controversial. Here, we report that the E3 ubiquitin ligase TRAF6 integrates innate immune signals following diet-induced obesity to promote glucose homeostasis through the induction of mitophagy. Whereas TRAF6 was dispensable for glucose homeostasis and pancreatic {beta}-cell function under basal conditions, TRAF6 was pivotal for insulin secretion, mitochondrial respiration, and increases in mitophagy following metabolic stress in both mouse and human islets. Indeed, TRAF6 was critical for the recruitment and function of machinery within both the ubiquitin-mediated (Parkin-dependent) and receptor-mediated (Parkin-independent) mitophagy pathways upon metabolic stress. Intriguingly, the effect of TRAF6 deficiency on glucose homeostasis and mitophagy was fully reversed by concomitant Parkin deficiency. Thus, our results implicate a role for TRAF6 in the cross-regulation of both ubiquitin-and receptor-mediated mitophagy through the restriction of Parkin. Together, we illustrate that {beta}-cells engage innate immune signaling to adaptively respond to a diabetogenic environment.

molecular biology↗

bioRxiv2025

Attenuated adenosine mediated immune-dampening increases natural killer cell activity in early age-related macular degeneration

Non-exudative age-related macular degeneration (AMD) involves retinal pigment epithelium (RPE) dysfunction and has been linked to altered intraocular immunity. Our investigation focuses on immune cell subsets and inflammation-associated factors in the eyes with early and intermediate AMD. We observed elevated levels of activated natural killer (NK) cells and interferon-{gamma}, concurrent with reduced myeloid-derived suppressor cells (MDSCs) and adenosine in AMD eyes. Aqueous humor from AMD patients had diminished ability to dampen NK cell activation, an effect rescued by adenosine supplementation. The Cryba1 cKO mouse model recapitulated these immune alterations, and single-cell RNA-sequencing identified NK cell-related genes and NK cell-RPE interactions. Co-culture of activated NK cells with RPE cells induced barrier dysfunction and Gasdermin-E driven pyroptosis providing a functional link relevant to AMD. These findings suggest a double-hit model where elevated immune activation and loss of immune dampening mechanisms drive AMD progression. Resetting the intraocular immune balance may be a promising therapeutic strategy for managing early and intermediate AMD. O_FIG O_LINKSMALLFIG WIDTH=198 HEIGHT=200 SRC="FIGDIR/small/634301v2_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@1516bfaorg.highwire.dtl.DTLVardef@87f505org.highwire.dtl.DTLVardef@1e725caorg.highwire.dtl.DTLVardef@622717_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstractC_FLOATNO Illustra tion of pro posed mechanism underlying NK cell-RPE interaction in early AMD pathogenesis. Dysregulated NK cell communicate s with stressed RPE in early AMD immunopathology. Aberrant AMD aqueous humor and retina shows increased NK cells and NK effector molecules like IFN{gamma} with reduced MDSC and adenosine in human subjects, don or eye and animal model. Activated NK cells interaction with RPE causes dysfunction and pyroptotic cell death via Gasdermin-E pathway in AMD.. Created with BioRender.com C_FIG

immunology↗

bioRxiv2025

LEVERAGING TRANSFER LEARNING FOR HIGH-ACCURACY PHENOTYPIC SCREENING IN ZEBRAFISH IMAGE ANALYSIS

This paper presents a method for classifying zebrafish images captured before and after drug administration. Leveraging the power of transfer learning and fine-tuning, the approach effectively overcomes the challenges of limited datasets in biomedical imaging. By employing a pre-trained convolutional neural network (CNN) as the base model, transfer learning allows us to utilize learned features from large-scale image datasets, significantly reducing training time and computational resources. Fine-tuning specific layers of the model on our zebrafish dataset further enhances its ability to detect subtle visual differences induced by drug administration. The proposed approach achieves high accuracy in classifying zebrafish images, demonstrating its potential as a reliable tool for analysing phenotypic changes due to pharmacological interventions. This model could be instrumental in accelerating drug discovery and research in zebrafish-based assays, offering a scalable and efficient solution for image-based biomedical analysis.

bioinformatics↗

bioRxiv2025

Light induces Phytochrome B SUMOylation to recruit the immune regulator NPR1 in nuclear condensates to control immunity in plants

It has long been observed that light perception by phytochromes control plant immunity, however, the underpinning molecular mechanism is less well understood. We demonstrate that light mediated SUMO conjugation to Phytochrome B (PhyB) is critical for increasing cellular salicylic-acid (SA) levels to orchestrate systemic acquired resistance (SAR) upon avirulent bacterial infection. SUMOylation is critical for PhyB nuclear condensate formation during light activated immunity. Light induced PhyB SUMOylation recruits NPR1, through its SUMO interacting motif to nuclear condensates to elevate SA levels for immune responses. In the dark during SAR, elevated SA levels substitute for light to maintain PhyB SUMOylation and immune-related photobody formation by stimulating the degradation of PhyB targeting deSUMOylase, OTS1. SUMOylated PhyB-NPR1 immune photobodies associate with TGA transcription factor associated chromatin to trigger immune gene expression. We unravel a mechanism where SUMOylation can enable light to recruit NPR1 to PhyB nuclear condensates to form immune photobodies to regulate plant immunity. HighlightsO_LILight-dependent immunity in plants relies on the SUMO mediated interaction between the photoreceptor PhyB and the Salicylic Acid (SA) receptor NPR1. C_LIO_LILight induced PhyB SUMOylation recruits NPR1 to nuclear condensates which we identify as immune photobodies that elevate SA levels for immune responses. C_LIO_LIIn darkness, SA can replace light in enabling PhyB-NPR1 immune photobody formation by regulating SUMOylation revealing a SA mediated mechanism for controlling PhyB liquid-liquid phase separation. C_LIO_LISUMO-modified PhyB-NPR1 immune photobodies regulate transcriptional activity of immune associated chromatin to shape defence responses in plants. C_LI

plant biology↗

bioRxiv2025

Development of a High-throughput Morphological Assay for Evaluating Mesenchymal Stromal Cell-derived Extracellular Vesicle Modulation of Brain Pericyte Secretory Phenotype

Mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) are a promising therapeutic tool for treating many neurodegenerative diseases. Neuroinflammation plays a major role in many of these conditions through an orchestration of interdependent processes that lead to the breakdown of the blood-brain barrier (BBB), infiltration of immune cells and neuronal death. MSC-EVs have shown preliminary evidence of modulating neuroinflammation, but their mechanisms of action are still unknown. Therefore, we explored the potential of MSC-EVs in modulating brain pericytes, a cell type that plays a critical role in BBB maintenance but has not been investigated as a therapeutic target for MSC-EVs. Brain pericytes are multifaceted cells that can modulate neuroinflammation through their involvement in BBB homeostasis, as well as the innate and adaptive immune response. Pericyte morphology has been shown to change in response to inflammatory stimuli in vivo, hence, we used this behavior to develop a quantitative morphological profiling approach to assess the immunomodulatory function of MSC-EVs in a high-throughput, low-cost manner. Using this assay, we were able to demonstrate that MSC-EVs manufactured under various conditions (2D, 3D, and in response to cytokine priming) could induce distinct pericyte morphological responses indicative of changes in secretion of chemokines and cytokines relevant to neuroinflammation.

bioengineering↗

bioRxiv2025

Identifying memory gene expression from single sample scRNA-seq data using power law signatures

Genes with expression levels that fluctuate on time scales longer than cell division times are associated with cancer drug tolerance. However, current methods for identifying such memory genes rely on variants of the Luria-Delbruck experiment and require either multiple replicates or lineage information, limiting their use to model systems or in-vitro settings. We develop a new conceptual approach using recent results in Random Matrix Theory to demonstrate that the existence of memory genes results in a power-law signature in the cell covariance matrix eigenspectrum. Utilizing this theoretical framework, we develop Power-Seek, an algorithm to discover memory genes from a single time point scRNA-seq dataset. Without using prior information on lineages or cell-cycle times, Power-Seek correctly identifies memory genes in a melanoma cell line. Our results open up the possibility of identifying expression states driving drug tolerance in real-world scenarios, as we demonstrate using data from a human breast cancer tissue sample.

biophysics↗

bioRxiv2024

Cell Morphology accurately predicts the nuclear shape of adherent cells

Cells are internally tensed, or prestressed, largely by actomyosin contractility. We hypothesized that nuclear shape is quantitatively predictable from cell shape since prestress couples them both. We trained machine learning models on a publicly available image database of the WTC-11 cell line and predicted shape modes of the nucleus with high accuracy. We develop a U-Net architecture-based model, Cell2Nuc, that predicted nuclear voxels from the cell membrane with accuracies between 74%-87%. To investigate prestress, we cultured and imaged HeLa cells after inhibiting actomyosin contractility. The Cell2Nuc model retrained on the HeLa cells predicted nuclear voxels with slightly lower accuracy. Statistical analysis revealed changes in nuclear size and chromatin organization upon prestress inhibition. Similar trends were seen in images taken from NIH3T3 cells. Thus, cell shape encodes features of nuclear shape, their coupling is partly due to actomyosin contractility, whose abrogation leads to changes in chromatin organization of mechanosensitive origin.

cell biology↗

bioRxiv2024

Precise and scalable metagenomic profiling with sample-tailored minimizer libraries

Reference-based metagenomic profiling requires large genome libraries to maximize detection and minimize false positives. However, as libraries grow, classification accuracy suffers, particularly in k-mer-based tools, as the growing overlap in genomic regions among organisms results in more high-level taxonomic assignments, blunting precision. To address this, we propose sample-tailored minimizer libraries, which improve on the minimizer-LCA (lowest common ancestor) classification algorithm from the widely used Kraken 2 [1]. In this method, an initial filtering step using a large library removes non-resemblance genomes, followed by a refined classification step using a dynamically built smaller minimizer library. This 2-step classification method shows significant performance improvements compared to the state of the art. We develop a new computational tool called Slacken, a distributed and highly scalable platform based on Apache Spark, to implement the 2-step classification method, which improves speed while keeping the cost per sample comparable to Kraken 2. Specifically, in the CAMI2 [2] "strain madness" samples, the fraction of reads classified at species level increased by 3.5x, while for in silico samples it increased by 2.2x. The 2-step method achieves the sensitivity of large genomic libraries and the specificity of smaller ones, unlocking the true potential of large reference libraries for metagenomic read profiling.

genomics↗

bioRxiv2024

Glycan analysis probes inspired by human lectins for investigating host-microbe crosstalk

Human lectins are critical carbohydrate-binding proteins that recognize diverse glycoconjugates from microorganisms and can play a key role in host-microbe interactions. Despite their importance in immune recognition and pathogen binding, the specific glycan ligands and functions of many human lectins remain poorly understood. Using previous proof-of-concept studies on selected lectins as the foundation for this work, we present ten additional glycan analysis probes (GAPs) from a diverse set of human soluble lectins, offering robust tools to investigate glycan-mediated interactions. We describe a protein engineering platform that enables scalable production of GAPs that maintain native-like conformations and oligomerization states, equipped with functional reporter tags for targeted glycan profiling. We demonstrate that the soluble GAP reagents can be used in various applications, including glycan array analysis, mucin- binding assays, tissue staining, and microbe binding in complex populations. These capabilities make GAPs valuable for dissecting interactions relevant to understanding host responses to microbes. The tools can be used to distinguish microbial from mammalian glycans, which is crucial for understanding the cross-target interactions of lectins in a physiological environment where both glycan types exist. GAPs have potential as diagnostic and prognostic tools for detecting glycan alterations in chronic diseases, microbial dysbiosis, and immune-related conditions.

biochemistry↗

bioRxiv2024

The Diverse Phenotypic and Mutational Landscape Induced by Fluoroquinolone Treatment

Despite extensive research on antibiotic resistance, the potential effects of antibiotic treatments on bacterial tolerance and resistance remain a significant concern. Although bacterial cells adopt a variety of mutational strategies to resist unfavorable circumstances, it is still unclear how antibiotic tolerance and resistance mechanisms affect bacterial fitness characteristics and whether evolved mutants exhibit similar properties across different cell populations subjected to the same conditions. Here, we used Escherichia coli, a fluoroquinolone antibiotic (ofloxacin), and adaptive laboratory evolutionary experiments to demonstrate that ofloxacin tolerance and resistance can evolve independently across different cell populations exposed to identical conditions. Fitness attributes, such as lag score, doubling time, competition score, and other metabolic features, were variably affected by antibiotic tolerance and resistance mechanisms. However, we did not observe strong and apparent correlations between fitness trade-offs and antibiotic tolerance and resistance. While our whole-genome sequencing identified some shared mutations, such as single nucleotide polymorphisms in the icd gene (a crucial citric acid cycle gene), evolved cell populations exhibited diverse genetic mutations without a clear pattern of a conserved evolutionary pathway. Our study also identifies unique phenotypes, such as those displaying significantly lower minimum inhibitory concentration levels compared to the parental strain yet showing remarkably high tolerance to the same antibiotic. Altogether, our study, examining the phenotypic and mutational landscapes of fluoroquinolone-induced strains, contributes to our understanding of complex bacterial adaptation mechanisms.

microbiology↗

bioRxiv2024

Frataxin deficiency in the astrocytes drives neurocognitive impairment in sickle cell disease mice

Individuals with sickle cell disease (SCD) suffer from a high burden of cerebrovascular lesions and cognitive impairment that vastly impact quality of life. Cerebrovascular lesions are characterized by microstructural neuroaxonal damage, but their pathogenesis has not been fully elucidated. Herein, we report that SCD mice (SS) have reduced expression of frataxin (FXN), a mitochondrial protein, in their astrocytes compared to control (AA) mice. Next, we generated chimeric mice with SS bone marrow and astrocyte-specific deletion of FXN (SSFXN-KO). Ex-vivo diffusion tensor magnetic resonance imaging and immunohistopathology of the brain showed that the SSFXN-KO mice have increased white matter neuroaxonal damage compared to the SS bone marrow chimera mice with wild-type FXN expression (SSFXN-WT). The SSFXN-KO mice also displayed poorer cognitive function as measured by the functional Y-maze and novel object recognition tests. Pharmacological induction of FXN by administration of insulin growth factor-1 improved cognitive function in the SSFXN-KO mice. Overall, our data demonstrate that FXN is a critical factor regulating neuroaxonal health and cognitive function in SCD mice. FXN may therefore be a novel pharmacologic target to prevent cerebrovascular complications in SCD.

neuroscience↗

bioRxiv2024

Assessing the efficacy of therapeutically promising combination of polymyxin B and triclosan against colistin resistant Klebsiella pneumoniae

Antimicrobial resistance (AMR) is one of the greatest public health challenges of the current time, and it is primarily associated with Gram-negative bacterial infections. Among these infections, Klebsiella pneumoniae is the most notorious bacterial pathogen in the context of AMR dissemination. In this dire circumstance, clinicians explored old regimes such as colistin to treat these multidrug-resistant infections; however, unfortunately, the resistance towards these last-resort drugs is also emerging rapidly. In this study, we examined the occurrence of colistin resistance in K. pneumoniae concerning its mechanism of resistance, chronology, and geographical distribution. We found that resistance towards these last-resort drugs, colistin and polymyxin B, is emerging rapidly, with evolving multiple mechanisms of resistance. While efforts continue to develop new antibacterial drugs, a combination of approved antibacterial drugs may be one of the most suitable strategies to fight against AMR in the current time-ticking situation. In this series, we evaluated the efficacy of a therapeutically viable combination of polymyxin B and triclosan using a set of standard antibacterial assays, used for in vitro preclinical efficacy. We found that the combination is highly effective in colistin-resistant clinical strains of K. pneumoniae, as triclosan sensitizes the pathogen towards polymyxin B. Furthermore, the results of additional complementary experiments, such as time-kill kinetics, biofilm inhibition, frequency of resistance, cell viability, and cytotoxicity assays, show very encouraging results for the feasibility and validation of this combination. Finally, we examined the presence of mutations in field isolates of K. pneumoniae FabI enzyme, as it has been hypothesized previously that triclosan may cause mutation in its binding target, FabI. Interestingly, we could not detect any mutation in the triclosan binding site of FabI in the genome of field isolates. Altogether, this study provides an overview of the current situation on colistin resistance, a promising solution for colistin resistance comprising a combination of two already being used antibacterial ingredients based on in vitro efficacy studies.

microbiology↗

bioRxiv2024

Frustration in the Protein-Protein interface Plays a Central Role in the Cooperativity of PROTAC Ternary Complexes

Targeted protein degradation of a protein of interest (POI) by Proteolysis Targeting Chimeras (PROTACs) is an attractive approach for dealing with formerly undruggable protein targets. PROTACs are heterobifunctional molecules that connect a POI-binding and an E3-ligase (E3) binding motif with a linker. The simultaneous binding and formation of a ternary POI::PROTAC::E3 complex (TC) induces proximity between the POI and the E3, allowing for POI-ubiquitination and subsequent induction of proteasomal degradation. Despite the availability of many three-dimensional structures of TCs, unveiling the structure-function relationships for the design of PROTACs remains a challenge. This is because the TCs can be dynamic with a complex conformational landscape that individual crystal structures may not capture. In this work, we used SMARCA2 as the POI and VHL as the E3-ligase and solved the X-ray crystal structures of the respective ternary complexes with four different PROTACs. Molecular dynamics (MD) simulations were used to show that the SMARCA2-VHL interface is flexible with multiple energy minima. The protein-protein (POI-E3) interactions are largely formed by residues located in structurally disordered loops in both VHL and SMARCA2. The residue pairs in the SMARCA2-VHL interface are frustrated, i.e., adopt a suboptimal energetic state. The number of frustrated residue pairs averaged over the MD ensemble shows a positive correlation with the experimentally determined cooperativity of the PROTACs. This indicates that protein-protein interface frustration can play an important role in PROTAC function. The TC ensembles of VHL, SMARCA2 and 11 different PROTACs were modeled by comparative modeling followed by MD. The frustration was subsequently calculated from the MD trajectories and correlated with the cooperativity. We found that identification of the dynamic protein-protein contacts and frustrated residue pairs in the interface can provide a rational framework for the structure-based design of PROTACs.

biophysics↗

bioRxiv2024

Metabolomic Response to Non-Steroidal Anti-Inflammatory Drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are popular choices for the mitigation of pain and inflammation; however, they are accompanied by side effects in the gastrointestinal and cardiovascular systems. We compared the effects of naproxen, a traditional NSAID, and celecoxib, a cyclooxygenase -2 (Cox-2) inhibitor, in humans. Our findings showed a decrease in tryptophan and kynurenine levels in plasma of volunteers treated with naproxen. We further validated this result in mice. Additionally, we find that the depression of tryptophan was independent of both Cox-1 and Cox-2 inhibition, but rather was due to the displacement of bound tryptophan by naproxen. Supplementation of tryptophan in naproxen-treated mice rescued fecal blood loss and inflammatory gene expression driven by IL-1{beta} in the heart.

systems biology↗