Biology subjects

Choudhary, N.

Publications and source records attributed to Choudhary, N..

15 recordsLinked to original sources

bioRxiv2026

XpBrew and PanXpresso - automatic RNA-seq processing workflow and comprehensive collection of gene expression data

Rapid developments in sequencing technologies have reduced the costs of transcriptomic experiments and resulted in a plethora of publicly available RNA-seq datasets. This is a valuable resource that can be harnessed to obtain novel biological insights through data upcycling. In this wake, we introduce XpBrew, an end-to-end Python workflow that was applied to generate PanXpresso, a comprehensive collection of gene expression datasets covering the taxonomic breadth of plants, animals, fungi, bacteria and archaea. XpBrew (https://github.com/PuckerLab/XpBrew) and PanXpresso (https://doi.org/10.60507/FK2/OBIGQH) are freely available.

bioinformatics↗

bioRxiv2026

Extraction-dependent bone proteomics reveals distinct stable and dynamic protein modules during early post-exposure degradation

Bone is a highly durable biological tissue widely used in forensic, archaeological, and anthropological investigations; however, efficient protein recovery and understanding of protein stability over time remain major challenges in skeletal proteomics. Here, we systematically evaluated three bone protein extraction workflows and integrated them with data-independent acquisition (DIA) mass spectrometry to assess proteome coverage, reproducibility, and temporal protein dynamics under environmentally exposed conditions. Comparative analysis demonstrated that extraction strategy is a primary determinant of detectable proteome composition. EDTA-based demineralization followed by SDS extraction provided the deepest proteome coverage and highest reproducibility, whereas guanidine hydrochloride extraction preferentially enriched collagen and extracellular matrix proteins. In contrast, acid-based extraction yielded limited protein recovery. Temporal profiling of bone samples collected at 10 and 45 days post-exposure revealed two distinct protein classes. A temporally stable module, enriched in collagens and extracellular matrix proteins including COL1A2, COL5A2, BGN, SPARCL1, and NID2, exhibited minimal abundance change, indicating resistance to environmental degradation. In contrast, temporally dynamic proteins, enriched in mitochondrial, metabolic, and intracellular pathways such as ACO2, OGDH, PDHA1, ATP5PO, and PFKM, showed marked decline over time. These findings support a two-compartment model of bone protein preservation in which matrix-embedded proteins are preferentially retained while exposed intracellular proteins undergo progressive degradation. Collectively, this study establishes an integrated framework linking extraction methodology with temporal proteome stability and identifies candidate markers for skeletal preservation assessment and temporal biomarker development in forensic and archaeological applications.

systems biology↗

bioRxiv2026

Integrated Metabolomic, Proteomic, and Phosphoproteomic Profiling Reveals CAMKK2-Dependent Regulation of Cell Cycle and Nucleotide Metabolism in Gastric Cancer

Gastric cancer is driven by aberrant kinase signaling that supports uncontrolled proliferation and metabolic adaptation. Calcium/calmodulin dependent protein kinase kinase 2 (CAMKK2) is overexpressed in gastric cancer; however, its role in regulating metabolic programs that sustain tumor growth remains incompletely understood. In this study, we employed an integrated multi-omics approach with a primary focus on untargeted metabolomics to investigate the consequences of CAMKK2 inhibition in gastric cancer cells. Pharmacological inhibition of CAMKK2 using STO-609 in AGS cells resulted in significant suppression of proliferation, clonogenic growth, migration, and invasion, accompanied by pronounced nuclear abnormalities and multinucleation indicative of mitotic defects. Global metabolomic profiling revealed extensive and time-dependent metabolic reprogramming following CAMKK2 inhibition, characterized by a marked depletion of nucleotide intermediates, including purine and pyrimidine metabolites required for DNA synthesis. Pathway enrichment analysis highlighted suppression of nucleotide metabolism, lipid metabolism, and central carbon metabolic pathways, indicating a broad impairment of biosynthetic capacity. Integration with proteomic and phosphoproteomic datasets demonstrated that metabolic alterations were accompanied by downregulation of DNA replication machinery and attenuation of kinase signaling pathways governing cell cycle progression. Protein metabolite interaction and docking analyses further supported functional coupling between nucleotide metabolites and key replication-associated enzymes, revealing disruption of metabolite enzyme interactions upon CAMKK2 inhibition. Collectively, these findings identify CAMKK2 as a critical regulator of metabolic programs that support DNA replication and cell cycle progression. Its inhibition induces replication stress through coordinated depletion of nucleotide pools and disruption of replication-associated signaling, leading to impaired proliferation and mitotic failure. These results highlight CAMKK2 as a potential therapeutic target for exploiting metabolic vulnerabilities in gastric cancer.

cancer biology↗

bioRxiv2026

Diet-conditioned microbiota enhances fecal microbiota transplantation efficacy in alcoholic liver disease through caproic acid-PPARα signaling

Background and AimFecal microbiota transplantation (FMT) in Alcohol-related liver disease (ALD) has shown therapeutic potential, with variable efficacy and unclear mechanism. Because dietary protein influences gut microbiota composition, we hypothesized that donor dietary preconditioning could enhance FMT efficacy. We therefore examined in a murine ALD model if high-protein donor diet improves FMT outcome. MethodsALD was induced in C57BL/6N mice using a Lieber-DeCarli ethanol diet combined with thioacetamide administration for 12 weeks. FMT was performed using stool from diet-modulated donors, and recovery was assessed on day7 post-FMT. Multi-omics analysis using 16s rRNA and mass spectroscopy was performed for Gut microbiota composition, plasma- and stool-metabolome, and hepatic proteomes. Multi-omics outcomes were validated in ALD animal and Huh7 hepatocytes. ResultsBoth protein-based FMTs improved ALD recovery; Veg-FMT demonstrated superior efficacy, significantly reducing hepatic injury (AST 1.2-fold, p=0.002; bilirubin 1.2-fold, p=0.03; steatosis 1.7-fold,p=0.01) and restoring gut barrier integrity (occludin 1.5-fold,p=0.04; mucin 2 2.2-fold, p=002; and plasma endotoxin 1.7-fold, p=0.02). A significant 2-fold increase was observed in Lachnospiraceae NK4A136, Coriobacteriaceae UCG-002, and short-chain fatty acids, particularly caproic acid. Functional validation confirmed that caproic acid promoted hepatic fatty acid {beta}-oxidation through PPAR-dependent mechanisms, reducing triglyceride accumulation and lipogenesis in both cellular and animal models. ConclusionDonor preconditioning with a plant-protein enriched diet enhances FMT efficacy in ALD by gut microbiota modulation with increased metabolites like caproic acid. These findings highlight a microbiota-metabolite-host axis through which diet-modulated FMT improves hepatic lipid metabolism and injury, and identifies a pathway via which FMT imparts its effect. SignificanceThis study identifies a mechanistic basis for improving fecal microbiota transplantation (FMT) efficacy in alcohol-related liver disease (ALD) by demonstrating that dietary preconditioning of donor microbiota improves therapeutic outcomes. We show that plant protein-modulated donor microbiota supplements abstinence-associated recovery through increased production of the microbial metabolite caproic acid, which promotes hepatic fatty acid {beta}-oxidation via PPAR signaling. These findings highlight donor dietary conditioning and microbiota-derived metabolites, rather than microbial composition alone, as important determinants of FMT efficacy. The results suggest that microbial metabolites such as caproic acid may represent potential therapeutic targets or biomarkers to enhance and standardize microbiota-based interventions in ALD. Although the current work is based on a murine model, the identified microbiota-metabolite-host metabolic axis provides a framework for future translational studies aimed at optimizing FMT strategies in liver disease.

microbiology↗

bioRxiv2025

Large-scale Phylogenomics Reveals Systematic Loss of Anthocyanin Biosynthesis Genes at the Family Level in Cucurbitaceae

O_LIPlant pigmentation secrets are among the oldest interests of plant scientists, with pigments such as chlorophyll, carotenoids, flavonoids, and betalains contributing to the diversity of hues in higher plants. Anthocyanins, a class of flavonoids responsible for vibrant shades of pink, red, and blue pigmentation, are almost ubiquitous in angiosperms but are replaced by betalains in some families in the order Caryophyllales. C_LIO_LIWe investigated anthocyanin pigmentation in Cucurbitaceae, one of the largest fruit and vegetable families, characterised by white and yellow flowers and red, orange, and green fruits predominantly pigmented by carotenoids. Using a comprehensive collection of 258 datasets representing 183 unique species across all 15 tribes of Cucurbitaceae, along with a phylogenomics approach, we observed a systematic absence of genes involved in anthocyanin and proanthocyanidin biosynthesis. Absence of the structural genes DFR, ANS, arGST, LAR, and ANR, along with the anthocyanin-related regulatory MYB genes, was consistently confirmed by synteny and phylogenetic analysis. C_LIO_LIThese results suggest that anthocyanin loss in angiosperms is more common than previously assumed. In light of this new discovery, we propose a stepwise loss of anthocyanin pigmentation in Cucurbitaceae, likely accompanied by a partial functional replacement with carotenoid pigmentation. C_LI

plant biology↗

bioRxiv2025

Evolutionary Rewiring of Anthocyanin Biosynthesis Pathway in Poaceae

Poaceae is a species-rich family of plants in the monocots harboring many important crop species. As grasses, these plants lack striking flowers that are typically pigmented by anthocyanins. Here, we investigated the anthocyanin biosynthesis genes in Poaceae and characterized several striking patterns. (1) An independently evolved MYB lineage (ncaMYB) is responsible for the regulation of the anthocyanin biosynthesis in Poaceae. (2) The independently evolved BZ2 lineage replaced the otherwise widespread TT19/An9 lineage as anthocyanin-related glutathione S-transferase in Poaceae. (3) The anthocyanin biosynthesis genes ANS, arGST (BZ2), and the anthocyanin biosynthesis activating MYB (ncaMYB) appear to be absent from the genus Brachypodium. These observations could be explained by a loss of the anthocyanin biosynthesis at the basis of the Poaceae, followed by an evolutionarily independent regain and again a loss of the anthocyanin biosynthesis in Brachypodium.

plant biology↗

bioRxiv2024

Cacao genome sequence reveals insights into the flavonoid biosynthesis

Theobroma cacao is well known for its role in producing cacao. Many different cacao varieties are cultivated in equatorial regions, each distinguished by unique phenotypic traits. One of these traits is pod color variation, which has been linked to differences in anthocyanin content. Anthocyanins are produced by a branch of the flavonoid biosynthesis pathway. In this study, two high-contiguity T. cacao genomes, BRAU1 and BONN1, were sequenced and assembled and used to investigate genes and structural variants associated with intraspecific variation in flavonoid biosynthesis. Comparative analysis identified structural variations affecting six candidate flavonoid biosynthesis genes, including a 1026 bp deletion at one of the DFR loci in BRAU1, BONN1, and Matina accessions.

plant biology↗

bioRxiv2024

Phylogenomics and metabolic engineering reveal a conserved gene cluster in Solanaceae plants for withanolide biosynthesis

Withanolides are steroidal lactones from nightshade (Solanaceae) plants. Of the over 1,200 known representatives, many possess potent biological activities, but their drug potential has not been fully realised up until now. A central obstacle is the limited availability of minor withanolides, caused by a lack of knowledge about the underlying biosynthetic pathways. Here, we combine phylogenomics with metabolic engineering to overcome this limitation. By sequencing the genome of the medicinal plant and archetypical withanolide producer ashwagandha (Withania somnifera) and comparing the genome sequences of nine Solanaceae species, we discovered a conserved gene cluster for withanolide biosynthesis, consisting of two sub-gene clusters which differ in their expression patterns. To investigate the functions of the encoded enzymes, we established metabolic engineering platforms in yeast (Saccharomyces cerevisiae) and the model plant Nicotiana benthamiana. This allowed us to reconstitute the first three oxidative steps of withanolide biosynthesis, catalysed by the cytochrome P450 monooxygenases CYP87G1, CYP88C7, and CYP749B2, leading to the aglycone of the known compound withanoside V. Our work sets the basis for the biotechnological production of withanolides in heterologous hosts and will therefore help to fully harness the drug potential of these plant steroids in the future.

plant biology↗

bioRxiv2023

Conserved amino acid residues and gene expression patterns associated with the substrate preferences of the competing enzymes FLS and DFR

BackgroundFlavonoids, an important class of specialized metabolites, are synthesized from phenylalanine and present in almost all plant species. Different branches of flavonoid biosynthesis lead to products like flavones, flavonols, anthocyanins, and proanthocyanidins. Dihydroflavonols form the branching point towards the production of non-colored flavonols via flavonol synthase (FLS) and colored anthocyanins via dihydroflavonol 4-reductase (DFR). Despite the wealth of publicly accessible data, there remains a gap in understanding the mechanisms that mitigate competition between FLS and DFR for the shared substrate, dihydroflavonols. ResultsAn angiosperm-wide comparison of FLS and DFR sequences revealed the amino acids at positions associated with the substrate specificity in both enzymes. A global analysis of the phylogenetic distribution of these amino acid residues revealed that monocots generally possess FLS with Y132 (FLSY) and DFR with N133 (DFRN). In contrast, dicots generally possess FLSH and DFRN, DFRD, and DFRA. DFRA, which restricts substrate preference to dihydrokaempferol, previously believed to be unique to strawberry species, is found to be more widespread in angiosperms and has evolved independently multiple times. Generally, angiosperm FLS appears to prefer dihydrokaempferol, whereas DFR appears to favor dihydroquercetin or dihydromyricetin. Moreover, in the FLS-DFR competition, the dominance of one over the other is observed, with typically only one gene being expressed at any given time. ConclusionThis study illustrates how almost mutually exclusive gene expression and substrate-preference determining residues could mitigate competition between FLS and DFR, delineates the evolution of these enzymes, and provides insights into mechanisms directing the metabolic flux of the flavonoid biosynthesis, with potential implications for ornamental plants and molecular breeding strategies.

plant biology↗

bioRxiv2023

Multi-omic screening of invasive GBM cells in engineered biomaterials and patient biopsies reveals targetable transsulfuration pathway alterations

While the poor prognosis of glioblastoma arises from the invasion of a subset of tumor cells, little is known of the metabolic alterations within these cells that fuel invasion. We integrated spatially addressable hydrogel biomaterial platforms, patient site-directed biopsies, and multi-omics analyses to define metabolic drivers of invasive glioblastoma cells. Metabolomics and lipidomics revealed elevations in the redox buffers cystathionine, hexosylceramides, and glucosyl ceramides in the invasive front of both hydrogel-cultured tumors and patient site-directed biopsies, with immunofluorescence indicating elevated reactive oxygen species (ROS) markers in invasive cells. Transcriptomics confirmed upregulation of ROS-producing and response genes at the invasive front in both hydrogel models and patient tumors. Amongst oncologic ROS, hydrogen peroxide specifically promoted glioblastoma invasion in 3D hydrogel spheroid cultures. A CRISPR metabolic gene screen revealed cystathionine gamma lyase (CTH), which converts cystathionine to the non-essential amino acid cysteine in the transsulfuration pathway, to be essential for glioblastoma invasion. Correspondingly, supplementing CTH knockdown cells with exogenous cysteine rescued invasion. Pharmacologic CTH inhibition suppressed glioblastoma invasion, while CTH knockdown slowed glioblastoma invasion in vivo. Our studies highlight the importance of ROS metabolism in invasive glioblastoma cells and support further exploration of the transsulfuration pathway as a mechanistic and therapeutic target.

cancer biology↗

bioRxiv2019

Deciphering the multi-scale mechanisms of Tephrosia purpurea against polycystic ovarian syndrome (PCOS) and its major psychiatric comorbidities: studies from network-pharmacological perspective

Tephrosia purpurea (T. purpurea), a plant belonging to Fabaceae (pea) family, is a well-known Ayurvedic herb and is commonly known as Sarapunkha in traditional Indian medicinal system. Described as \"Sarwa wranvishapaka\", i.e. having capability to heal all types of wounds, it is particularly recognized for its usage in splenomegaly. Towards exploring the comprehensive effects of T. purpurea against polycystic ovarian syndrome (PCOS), its phytochemicals were extensively reviewed and their network pharmacology evaluation is carried out in this study. The complex regulatory potential of its 76 phytochemicals (PCs) against PCOS are enquired by developing and analyzing high confidence tripartite networks of protein targets of each phytochemical at both pathway and disease association scales. We also developed a high-confidence human PPI sub-network specific to PCOS, explored its modular architecture and probed the drug-like phytochemicals (DPCs) having multi-module regulatory potential. The proteins belonging to endocrine system were identified as major targets of the PCs. The study reports 30 DPCs based on ADMET and drug-like properties. Multi-targeting and synergistic capacities of the 12 DPCs against 10 protein targets were identified and evaluated using molecular docking and interaction analyses. The study concludes by highlighting a couple of DPCs as potential sources of PCOS regulators.

systems biology↗

bioRxiv2019

Anastrozole mediated modulation of mitochondrial activity by inhibition of mitochondrial permeability transition pore opening: An initial perspective

BackgroundMitochondrial permeability transmembrane pore [mPTP] plays a vital role in alteration of the structure and function of mitochondria. Cyclophillin D is a mitochondrial protein that regulates mPTP function and a known drug target for therapeutic studies involving mitochondria. While aromatase inhibitors role on mPTP has been previously studied, the role of anastrazole on mPTP is not completely elucidated.\n\nMethodsThe role of anastrozole in modulating the mPTP was evaluated by docking and molecular dynamics using human cyclophillin D data. Peripheral blood mononuclear cells [PBMCs] of patients with mitochondrial disorders and healthy controls were treated with anastrazole and evaluated for mean fluorescence by flow cytometer. Spectrophotometry was employed for total ATP level estimation.\n\nFindingsAnastrozole - cyclophillin D complex is more stable when compared to cyclosporine A - cyclophillin D. Anastrozole performed better than cyclosporine in inhibiting mPTP pore. Additional effects included reduction in mitochondrial swelling and mitochondrial membrane depolarization, decreased super oxide generations, caspase 3 intrinsic activity and cellular apoptosis levels and increase in ATP levels.\n\nInterpretationThese results highlights the potency of anastrozole as a promising agent in ameliorating the phenotype by inhibiting the opening of mPTP pore. However, larger functional studies are required to validate the efficacy of this molecule as a therapeutic agent in mitochondrial disorders.

molecular biology↗

bioRxiv2019

Oral clade C SHIV challenge models to study pediatric HIV-1 infection by breastmilk transmission

Nonhuman primate (NHP) models are invaluable for HIV pathogenesis, intervention and cure studies. To enhance the translational potential of NHP HIV vaccine studies, clinically relevant R5-tropic, tier 2 neutralization sensitive, and mucosally transmissible simian-human immunodeficiency viruses (SHIVs) have been designed. Towards our goal of developing vaccines to prevent breastmilk transmission of HIV, we evaluated virological outcomes of three distinct SHIVs in repeated weekly oral exposure regimens in infant rhesus macaques. The selected strains SHIV-1157ipd3N4, SHIV-1157(QNE)Y173H, and SHIV CH505 375H.dCT express a clade C HIV Env, the clade most prevalent in regions with high pediatric HIV infections. All three SHIVs were orally transmissible. However, compared to the pediatric SIVmac251 model, SHIV replication was more attenuated. Some animals exposed to weekly low-dose (20 TCID50) SHIV-1157ipd3N4 had transient viremia blips associated with lack or delayed seroconversion. Animals with acute viremia [≥]10,000 viral RNA copies/ml seroconverted. This finding was reminiscent of an earlier study suggesting to continue challenges until a threshold of [≥]10,000 viral RNA copies/ml is surpassed to achieve seroconversion, one criterion of HIV diagnosis. All animals exposed weekly with higher doses (>104 TCID50) of SHIV-1157(QNE)Y173H or SHIV CH505 375h.dCT developed persistent infection with high peak viremia and seroconverted. Chronic viremia varied widely in all three SHIV infection models. Thus, although R5 clade C SHIVs are excellent tools to study prevention of virus acquisition, secondary virological outcomes of vaccine efficacy (e.g. risk of infection per exposure, modulation of peak viremia, viral set point) will require careful consideration and validation in SHIV challenge models. IMPORTANCEThe development of an effective HIV vaccine remains a top priority towards the goal of reducing the number of new HIV infections. Studies in nonhuman primate models of HIV infection have been instrumental in the preclinical evaluation of candidate vaccines. To assess the role of HIV Env-specific antibodies with broadly neutralizing or Fc-mediated effector function in these NHP models, the development and optimization of novel SHIV challenge models is required. We evaluate three different clade C HIV Env SHIVs for infectivity of infant macaques by the oral route. Our results demonstrate that SHIV-1157ipd3N4, SHIV-1157(QNE)Y173H, and SHIV CH505 375H.dCT can be orally transmitted and establish persistent infection in infant rhesus macaques, but chronic viremia levels vary widely. Therefore, SHIV infection models are most pertinent when prevention of systemic infection is the primary readout of vaccine efficacy, but secondary outcome measures of vaccine efficacy will require stringent criteria and extensive validation.

microbiology↗

bioRxiv2018

Identification of multi-targeting and synergistic neuromodulators of epilepsy associated protein-targets in Ayurvedic herbs using network pharmacological approach

Epilepsy comprises a wide spectrum of neuronal disorders and accounts for about one percent of global disease burden affecting people of all age groups. In the traditional medicinal system of Indian antiquity, commonly known as Ayurveda, epilepsy is recognised as apasmara and a plenty of information is documented regarding the effectiveness of various herbs against it. Towards exploring the complex regulatory mechanisms of Ayurvedic herbs at molecular levels, in this study, a network pharmacological framework is developed for thoroughly examining the anti-epileptic potential of 349 drug-like phytochemicals (DPCs) found in 63Ayurvedic herbs. Interaction networks of phytochemicals in anti-epileptic herbs, their protein targets and associated human pathways are designed at various scales and DPCs are mapped on these networks to uncover complex interrelationships. Neuromodulatory prospects of anti-epileptic herbs are probed and, as a special case study, DPCs that can regulate metabotrophic glutamate receptors (mGluRs) are inspected. An account of novel regulatory phytochemicals against epilepsy is reported by systematically analysing the screened DPCs against DrugBank compounds. A repertoire of DPCs having poly-pharmacological similarity with anti-epileptic drugs available in DrugBank and those under clinical trials is also reported. Further, a high-confidence PPI network specific to the protein targets of epilepsy was developed and the potential of DPCs to regulate its functional modules was investigated. The study concludes by highlighting a couple of herbs as potential sources of epileptogenic regulators. We believe that the presented schema can open-up the exhaustive explorations of indigenous herbs towards meticulous identification of DPCs against various diseases and disorders.

systems biology↗

bioRxiv2017

Piper longum Linn: A review of its phytochemicals and their network pharmacological evaluation

Piper longum L. (P. longum, also called as long pepper) is one of the common culinary herb and has been extensively used as an important constituent of various indigenous medicines, specifically in traditional Indian medicinal system known as Ayurveda. Towards obtaining a global regulatory framework of P. longums constituents, in this work we first reviewed phytochemicals present in this herb and then studied their pharmacological and medicinal features using network pharmacology approach. We developed high-confidence level tripartite networks consisting of phytochemicals - protein targets - disease association and explain the role of its phytochemicals to various chronic diseases. 7 drug-like phytochemicals in this herb were found as the potential regulators of 5 FDA approved drug targets; and 28 novel drug targets were also reported. 105 phytochemicals were linked with immunomodulatory potency by pathway level mapping in human metabolic network. A sub-network of human PPI regulated by its phytochemicals was derived and various modules in this sub-network were successfully associated with specific diseases.\n\nGraphical abstract\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=159 SRC=\"FIGDIR/small/169763_ufig1.gif\" ALT=\"Figure 1000\">\nView larger version (37K):\norg.highwire.dtl.DTLVardef@1254f37org.highwire.dtl.DTLVardef@73aeb9org.highwire.dtl.DTLVardef@d416cborg.highwire.dtl.DTLVardef@246ced_HPS_FORMAT_FIGEXP M_FIG C_FIG Abbreviations

systems biology↗