Biology subjects

Das, S.

Publications and source records attributed to Das, S..

At least 91 records · Page 5Linked to original sources

bioRxiv2025

Profiling miRNAs involved in Human Oligodendrocyte Precursor Cell Differentiation and Maturation

MicroRNAs (miRNAs) are evolutionarily conserved post-transcriptional regulators that play critical roles in cellular development and differentiation across species. Although the importance of miRNAs in oligodendrocyte lineage cell (OLLC) differentiation has been extensively studied in rodent models, their roles in human OL development remain less understood. To address this gap, we used a human embryonic stem cell (hESC) reporter system designed to study human OLs and OL progenitor cells (OPCs). Using an optimized differentiation protocol, we used the reporter hESCs to generate and isolate well-characterized OLLCs at specific developmental stages and performed next-generation sequencing-based miRNA profiling to identify stage-specific miRNAs enriched during OL lineage specification and maturation. In addition to canonical miRNAs known to be enriched at various stages of OL development, our study identified several lesser-known miRNAs with distinct stage-specific enrichment patterns that may serve as useful molecular markers for classifying human CNS cell types in future studies. Target analysis of OPC-and OL-enriched miRNAs revealed key genes, including transcription factors ZNF488 and DLX1, cytoskeletal regulator CSNK2B, and potassium channel gene KCNJ1, along with key signaling pathways such as AKT, SMAD2/3, estrogen receptor, and insulin signaling, which regulate OPC and OL lineage function. These findings advance our understanding of the OLLC-specific miRNAs, and miRNA-mediated regulatory networks governing human OL differentiation and maturation and provide promising therapeutic targets for future studies aimed at restoring myelin integrity and improving outcomes in demyelinating diseases.

neuroscience↗

bioRxiv2025

Decision revisions modulated by synaptic inhibition in the olfactory bulb facilitate learning

Behavioral responses are preceded by decisions based on perceived sensory evidence. In real life, sensory inputs are often noisy and change incessantly, raising the question of when and how accurate decisions are made. Cognitive flexibility allows us to revise the choices in case of perceptual conflicts, leading to response revisions. This involves switching between available choices or rapidly stopping misconstrued responses. Here, we quantified these erroneous behavioral actions and studied the underlying neural mechanisms. Mice were trained on an olfactory decision-making task wherein they had to distinguish between a rewarded and an unrewarded stimulus by responding with a lick or withholding it. While the animals respond by licking for both rewarded and unrewarded odor stimuli at the initial stages of learning, the responses almost disappear for the unrewarded ones in the learned stage. However, animals tend to initiate lick responses and stop within a few milliseconds for a few unrewarded trials, even when accuracy levels are high. We describe this phenomenon as decision revisions (DR), and observed it in 5-25% of trials among high-performance blocks. These revisions were mostly observed within a few hundred milliseconds of stimulation. We observed a significantly higher number of revision trials for binary odor mixture discriminations compared to monomolecular ones. Further, by enhancing inhibitory synaptic signaling in the olfactory bulb through photoactivation of ChR2-expressing GAD65-positive GABAergic interneurons, we observed faster odor discrimination and fewer revision trials. Thus, our findings confirm decision revisions that are stimulus complexity-dependent and the pre-cortical control over such a complex cognitive activity. Highlights of the studyO_LIMice revise context-inappropriate responses in a Go/No-go task. C_LIO_LIMice correct errors as they learn. C_LIO_LIDecision revisions are shaped by stimulus complexity. C_LIO_LIOptogenetic activation of the olfactory bulb inhibitory interneurons modulates decision revisions. C_LI

neuroscience↗

bioRxiv2025

Cardiolipin Remodeling as a Regulatory Switch in Osteogenesis: Insights from Multimodal Metabolic Imaging and Molecular Profiling

Cardiolipin (CL), a mitochondria-specific phospholipid, plays a fundamental role in respiratory chain organization and bioenergetic efficiency, yet its contribution to osteogenic differentiation is poorly defined. Here, we used a multimodal approach integrating untargeted LC-MS lipidomics, Raman spectroscopy, fluorescence lifetime imaging microscopy (FLIM), and structural imaging to investigate CL remodeling during human adipose-derived stem cell differentiation. Lipidomics revealed a selective enrichment of highly unsaturated CL species, accompanied by transcriptional upregulation of the cardiolipin biosynthetic and remodeling enzymes CDS1/2, PGS1, CRLS1, TAZ, and HADHA. Lipidomics also revealed a time-dependent increase in membrane-associated lipids including phosphatidylcholine (PC), serine, and phosphatidylinositol (PI). These lipids were implicated in supporting mitochondrial membrane expansion, oxidative phosphorylation, and signaling processes critical for osteoblast maturation. Spatial imaging techniques confirmed cardiolipin accumulation and redistribution in differentiated cells, while Raman-based direct classical least squares (DCLS) analysis provided label-free mapping of lipid species. Gene Ontology (GO) enrichment and protein-protein interaction network analysis further identified biological pathways related to bone remodeling, cardiolipin metabolism, and osteoblast-specific signaling. Fluorescence Lifetime Imaging Microscopy (FLIM) data revealed a metabolic shift from glycolysis to oxidative phosphorylation during differentiation, supported by structural and gene expression evidence. These changes temporally coincided with matrix mineralization and collagen organization, linking CL metabolism to both cellular bioenergetics and extracellular matrix production. Our findings identify cardiolipin remodeling as a metabolic checkpoint in osteogenesis and suggest that targeted modulation of CL pathways may provide new therapeutic strategies for enhancing bone regeneration.

cell biology↗

bioRxiv2025

Tuberculous meningitis alters the proteomic landscape of brain-derived extracellular vesicles

Tuberculous meningitis (TB meningitis), the deadliest form of Mycobacterium tuberculosis infection, leads to mortality and severe neurological disability despite standard therapy. Brain injury and microglial activation are major determinants of outcome, yet the mechanisms linking infection, inflammation and neuronal injury remain poorly understood. Extracellular vesicles (EVs), key mediators of cell-to-cell communication, have been investigated in pulmonary TB but their role in TB meningitis remains unexplored. We used our young rabbit model of TB meningitis to isolate pure, intact EVs from brain tissue (i.e., brain-derived EVs) from infected and uninfected rabbits and used nanoflow cytometry, transmission electron microscopy and protein quantification to characterize the EVs. Comparative proteomic profiling was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), followed by in silico pathway, cell-type and protein-protein interaction analyses using DAVID, Enrichr, and STRING databases. We found that EV isolation from fresh and frozen tissue was equivalent and demonstrated that M. tuberculosis infection activated EV biogenesis. Despite preserved vesicle morphology, EVs from infected brain showed a significant proteomic shift characterized by enrichment of TB host defense, microglial and immune activation, metabolic excitotoxicity, and neuronal injury. These proteome dysregulations suggest that infection reprograms brain EV cargo toward proinflammatory and metabolic stress responses while depleting neuronal and mitochondrial components. Collectively, these data demonstrate that M. tuberculosis infection alters the cargo and abundance of brain-derived EV, highlighting their potential as biomarkers and mediators of host-pathogen interactions in TB meningitis.

microbiology↗

bioRxiv2025

Potential probiotic application of a novel commensal E. coli with antagonistic activity against different enteric pathogens

Diarrheal diseases remain a leading cause of global morbidity and mortality, and treatment options are increasingly compromised by the global rise in multidrug-resistant (MDR) pathogens. Furthermore, the absence of effective vaccines against many causative agents renders large populations vulnerable. This critical gap necessitates the development of novel alternatives that can function both prophylactically to prevent infection and therapeutically to treat established diseases. Here, we investigated the commensal Escherichia coli strain HK220822 (HK5), which was isolated from a healthy human, as a potential live biotherapeutic. Comprehensive genomic and phenotypic characterization established a robust safety profile, confirming the absence of key virulence genes while demonstrating essential probiotic traits, including high tolerance to gastrointestinal stressors, such as acid and bile. The functional efficacy of Escherichia coli HK5 has been validated in murine models of infection. Prophylactic administration before pathogen exposure significantly inhibited intestinal colonization by Salmonella Typhimurium, Shigella flexneri 2a, and Vibrio cholerae (El Tor O1 strain). Moreover, HK5 demonstrated therapeutic potential by significantly reducing pathogen shedding when administered to previously infected animals. These findings establish commensal E. coli (HK5) as a potent candidate with dual preventative and therapeutic efficacy, offering a promising non-antibiotic strategy to combat diarrheal diseases.

microbiology↗

bioRxiv2025

Interaction and co-phase separation of SARS-CoV-2 nucleocapsid protein and human hnRNPA1 and its implications for viral life cycle

The nucleocapsid (N) protein of SARS-CoV-2 is central to viral assembly and replication. It binds viral RNA to form a helical nucleocapsid and enabling genome packaging and release into host cells. Human hnRNPA1, one of the most abundant RNA-binding proteins in eukaryotes, regulates key aspects of RNA metabolism, including splicing, transcription, localisation, and transport. Here, we report a direct physical interaction between SARS-CoV-2 N protein and hnRNPA1 with moderate affinity (Kd [~] 0.18 M), primarily mediated through their intrinsically disordered regions. Furthermore, we found that these proteins co-phase separate in vitro and co-localise within stress granules in cells. In vivo studies reveal that hnRNPA1 suppresses viral replication, suggesting that the N protein - hnRNPA1 interaction plays an important role in modulating the viral life cycle.

biochemistry↗

bioRxiv2025

Biophysical Design Space for Cellular Self-assembly and Dynamics

In natural biological systems, cells organize into tissues through interactions of several processes, including cellular signaling, collective migration, contractile activity of cytoskeletal elements and interactions with their surroundings. In recent decades, advancements in microscopy, genetic engineering, biochemistry, and computational modeling have enabled a more quantitative understanding of these processes. In this article, we present an integrated computational framework that couples various physical mechanisms such as cell-cell adhesion, strength and persistence of cellular motility, and the background stiffness. We use this framework to study how they collectively interact to determine the self-organization of the cells from a pseudo-random structure as well as the migration behavior of the cells. Notably, our simulations predict that motility has a two-way effect on cellular self-assembly: it promotes aggregation at moderate levels but disrupts clusters when excessively strong, yielding an optimal motility for formation of multicellular clusters. On the other hand, adhesion shows a two-stage effect: At lower value it self-assembles the structure, at higher value it compacts it. Furthermore, we experimentally demonstrate the motility-assisted self-aggregation of cells using cancer cells in a granular mechanical milieu. Finally we show that cell-cell adhesion and background medium tune the strength and persistence of cellular migration. Altogether, this work presents a computational framework that allows us to design phase behavior of collective of cells tuning their interaction, motility, and the background mechanics.

biophysics↗

bioRxiv2025

From Lab to Industry: Awareness of the translational potential of Extracellular Vesicles by the ISEV Translation, Regulation and Advocacy Committee (ISEV-TRA).

Extracellular vesicles (EVs) are critical mediators of cellular communication, with significant potential for disease diagnosis, therapeutics, and other industrial applications. However, translating EV-based innovations into real-world products faces substantial challenges, particularly concerning regulatory frameworks and scientific gaps. To address these issues, the International Society for Extracellular Vesicles (ISEV) established the Translation, Regulation, and Advocacy Committee (ISEV-TRA) to create an environment that facilitates the translation of EV research into practical societal applications. This reporet presents the results of the first survey conducted by the ISEV-TRA, assessing the degree to which EVs have been translated into society applications, awareness of EV potential, and the current use of EVs across various industry sectors. Respondents included individuals from Academia, Industry, and dual affiliation (Academia-Industry), provided an initial perspective on EV research and its translational status. The survey highlights the growing interest in EV-based products, suggesting that there is an important wave of efforts to develop these products. Several spin-outs created by academic researchers are focusing on EV-based products, a key trend in the field, while large companies are showing increasing interest in EV-based technologies. The expectations and suggestions for the newly established ISEV-TRA underscore the need for a unified approach to accelerate the translation of EV-based technologies into practical applications. The ISEV-TRA is well-positioned to play a key role by providing essential resources, organizing workshops, and promoting interdisciplinary collaboration, ultimately driving the commercialization of EV-based innovations.

scientific communication and education↗

bioRxiv2025

State-dependent release of extracellular particles with distinct α2,6-sialylation patterns and small RNA cargo related to neuroinflammation

Neuroinflammation is a significant contributor to neurodegenerative diseases, including Alzheimers disease, Parkinsons disease, and related dementias; yet peripheral biomarkers for neuroinflammation remain an unmet medical need. Microglia, the resident immune cells of the central nervous system, play a dual role in maintaining homeostasis under physiological conditions and driving neuronal damage when chronically dysregulated. One mechanism by which microglia influence their environment is through the release of extracellular vesicles (EVs) and non-vesicular extracellular particles (NVEPs), which can serve as biomarkers the reflect cellular states. Here, we systematically isolated and characterized microglia-derived EVs and NVEPs under pro- and anti-inflammatory conditions and profiled their small RNA cargo by small RNA sequencing. We validated these findings in human iPSC-derived microglia and further recapitulated them in EVs and NVEPs from mouse brain and plasma. Using an engineered mouse model, we were able to isolate plasma microglia-specific EVs in vivo and demonstrated that their RNA cargo reflects their inflammatory state. Importantly, microglial EVs and NVEPs display distinct 2,6-sialylation patterns and small RNA signatures implicated in neurological diseases. These findings demonstrate that microglia-derived EVs and NVEPs cargo reflect microglial cellular state and establish them as putative minimally non-invasive biomarkers of early-stage neurodegenerative diseases.

neuroscience↗

bioRxiv2025

A closely related pair of superoxide dismutase isozymes from Staphylococcus aureus show distinct stabilities and proton-exchange dynamics

Changes in biochemical properties, caused by iterative mutations in amino acid sequence, underlie the alterations in protein function over time that underpin the evolutionary process. An example is the switching of an enzymes reliance from one essential metal to an alternative as their catalytic cofactor. We previously described such a neofunctionalisation in Staphylococcus aureus, which altered a superoxide dismutase (SOD) enzyme from being an ancestral manganese-dependent (MnSOD) into an extant isozyme that can equally utilise either manganese or iron, termed cambialism (camSOD). Yet its unclear whether camSOD emergence involved selection solely for cofactor flexibility or whether other biochemical properties also diverged during neofunctionalisation. Here, we have investigated an independent biochemical property of the S. aureus SODs, their structural stability. We demonstrate that the neofunctionalised camSOD exhibits increased stability relative to the ancestral MnSOD. S. aureus camSOD is more resistant to both chemical and thermal unfolding in vitro. Crucially, while both isozymes possess a stable core at the heart of their fold, consisting of regions of the protein localised around the metal cofactor that resist hydrogen-deuterium exchange when exposed to isotopically labelled solvent, this core is larger and more exchange-resistant in camSOD than MnSOD. Thus, during the recent divergence of this SOD pair, two distinct biochemical properties have undergone substantial and rapid evolutionary change. This study paves the way for investigations of the structural and functional relationship between these properties, a SODs metal-preference and stability, and of how these properties were concomitantly selected during neofunctionalisation in the S. aureus lineage.

biochemistry↗

bioRxiv2025

Exploring Size Exclusion Chromatography Columns 20 and 35 nm Pore Size Effect for Isolation of Extracellular Vesicles

Extracellular vesicles (EVs) have shown great promise as minimally invasive biomarkers for a variety of diseases. However, challenges persist regarding EV isolation, particularly in their co-isolation with impurities such as soluble proteins and lipoproteins. Among the methods available for EV isolation, size-exclusion chromatography (SEC) is widely used, as it is reproducible and amenable to high-throughput with a rapid turnaround time. However, its size-based separation leads to the co-isolation of EVs with impurities of similar size. This study, for the first time to our knowledge, compares SEC columns with different pore sizes, 20 and 35 nm, to evaluate their efficacy in non-EV contaminant removal and EV recovery from pancreatic EndoC-{beta}H1 cell culture media and human plasma. To assess EV purity and yield, we compare EV particle concentration, the presence of unintended co-isolates, and RNA EV cargo. This study demonstrates that smaller pore size SEC columns enhance EV yield and purity, making them ideal for biomarker studies involving limited biological samples or downstream analysis sensitive to contaminants.

biochemistry↗

bioRxiv2025

Resting-state functional MRI derivatives: A dataset derived from the The Comprehensive Assessment of Neurodegeneration and Dementia Study

Resting-state functional connectivity (RSFC) holds promise for the detection and characterisation of dementia. The Comprehensive Assessment of Neurodegeneration and Dementia (COMPASS-ND) Study, by the Canadian Consortium on Neurodegeneration in Aging (CCNA), provides a unique resource to study deeply phenotyped neurodegenerative conditions. We present RSFC derivatives for 784 participants (data release 7 of the cohort) who were either cognitively unimpaired or diagnosed primarily with Alzheimers disease (AD), mixed dementia (AD with a vascular component), mild cognitive impairment (MCI), vascular MCI, frontotemporal dementia, Parkinsons disease with or without MCI or dementia, Lewy body disease or subjective cognitive impairment. Functional MRI scans were preprocessed using fMRIPrep, and time-series and whole-brain connectomes generated using three atlases at multiple resolutions, denoised using seven different techniques. High-motion artifacts were managed using a liberal quality control threshold appropriate for an older clinical population, resulting in data from 680 participants. These derivatives are made available to the research community to accelerate research on RSFC biomarkers of neurodegenerative disease, reducing duplication of effort, saving computational resources, and improving standardisation across studies.

neuroscience↗

bioRxiv2025

LoAR-Exo and HiAR-Exo: One-step label-free isolation of extracellular vesicles using inertial microfluidic devices

Extracellular vesicles (EVs) are lipid membrane-bound nanoscale (20 nm - 1000 nm) objects shed by all cells. As EVs play an important role in intercellular signaling, these have emerged as promising biomarkers for many diseases including cancer and neurodegenerative disorders. A major bottleneck in research into EVs and their smooth translation to clinic as disease biomarkers is a lack of access to affordable and user-friendly technologies to quickly isolate EVs from complex biological and clinical samples with acceptable purity and yield. Here, we report two different designs of inertial microfluidic devices (e.g. LoAR-Exo and HiAR-Exo) that can isolate EVs from different kinds of biological samples in a single label-free step using a spiral microchannel design with different aspect ratios. LoAR-Exo has a height-to-width aspect ratio [~] 1, while HiAR-Exo has a height-to-width aspect ratio of 2.5, optimized by COMSOL simulations. We tested both designs by separating polystyrene particles of size < 1 m from a heterogeneous mixture. We then benchmarked the performance of the microfluidic chips against ultracentrifugation and a precipitation kit by isolating EVs from the cell culture-conditioned media (CCM) of MDA-MB-231 cells. We also compared the microchip with SEC by using the CCM from H1975/OR cells. The size distribution of EVs isolated by the microfluidic chip was comparable with ultracentrifugation, precipitation and SEC. In summary, both devices isolated EVs from as little as 1 mL of sample volume using a label-free technique in a continuous manner and without any user intervention. Both microfluidic platforms offer a simple, efficient, and scalable alternative to conventional methods for EV isolation.

bioengineering↗

bioRxiv2025

Deciphering the Interaction Between Dvl2 and Profilin2: Effector Molecules of Non-Canonical Wnt Signaling

Wnt signalling is a cornerstone of embryonic development, orchestrating critical processes such as body axis formation, gastrulation, and organogenesis through conserved canonical and non-canonical pathways. Dishevelled (Dvl), a central mediator of these pathways, contains conserved DIX, PDZ, and DEP domains, along with an extreme-C-terminus. Recent studies suggest that the extreme-C-terminus regulates non-canonical Wnt signalling via an autoinhibitory interaction with the PDZ domain. Non-canonical Wnt signalling branches into the planar cell polarity (PCP) and Wnt/Ca{superscript 2} pathways. Profilin, a monomeric actin-binding protein, has been implicated in PCP signalling through Daam1-mediated actin polymerization, whereas its silencing disrupts the Wnt/Ca{superscript 2} pathway in a Daam1-independent manner, pointing to a role for profilin upstream of Daam1. In this study, we identify a novel interaction between Dvl2 and profilin2. Co-localization and in vitro pull-down assays demonstrate that profilin2 directly interacts with Dvl2. Furthermore, our study reveals profilin2 binds specifically to the extreme-C-terminus of Dvl2, beyond the polyproline motif, without engaging the PDZ or DEP domains. This challenges the conventional view of profilin-polyproline interactions and highlights the existence of previously unrecognized molecular determinants. Moreover, we show that Dvl2 adopts an autoinhibited conformation through intramolecular binding of its extreme-C-terminus to the PDZ domain. Remarkably, profilin2 retains its binding ability even in this autoinhibited state. Together, these findings uncover a previously unrecognized profilin2-Dvl2 interaction and provide new mechanistic insights into the molecular regulation of non-canonical Wnt signalling.

developmental biology↗

bioRxiv2025

Gene-centric metagenomic analyses reveal microbiome functional insights into diseases

The microbiome encodes millions of genes; however, understanding their role in human health remains challenging. Here, we developed MetaGEAR, a gene-centric analysis framework for metagenomic data. MetaGEAR constructs cohort-specific databases for efficient retrieval of gene annotations, abundances, and co-localization, while providing enhanced taxonomic resolution by integrating reference- and assembly-based approaches. This is combined with a Metagenomic Assembled Graph (MAGraph) capturing gene neighborhood information. Using MetaGEAR, we built a multi-cohort database comprising >33 million gene families to investigate microbiome functionality across 24 cohorts of inflammatory bowel disease, colorectal cancer, and healthy populations and identified disease signature genes. Furthermore, the MAGraph revealed mobile genetic elements acting as hubs for tetracycline resistance spreading among Enterococcus, Streptococcus, and Veillonella species. Also, a duplicated nitrate reduction operon in Klebsiella pneumoniae was linked to differential gene expression under stress and virulence-inducing conditions. In summary, gene-centric metagenomic analyses reveal important insights into microbiome functionality in diseases.

microbiology↗

bioRxiv2025

RB1 gene mutations and their association with Endometrial Cancer

Retinoblastoma gene (RB1) mutation has been reported in lung cancer, retinoblastoma and cervical cancer etc. Here, we elucidate the involvement of RB1 mutations and their regulation in endometrial cancer. Analysis of mutation data of 547 endometrial cancer samples revealed that 12% of samples harboured RB1 mutations. However, 26% of the patients aged between 30 and 50 years harboured RB1 mutations, compared to only 10% in the older age group. Further, in silico interaction studies and structural analysis of these novel RB1 mutations and E2F revealed possible physiological relevance. We found 14,117 genes were significantly mutated, and 5,770 genes were differentially expressed in RB1-altered patients. Pathway analysis showed a significant correlation between RB1 mutations and estrogen receptor mutations. Different cancer-related pathways were also altered in RB1-mutated conditions. More importantly, a positive link between RB1 mutations and HPV infection pathways was observed, indicating HPV infections might induce RB1 mutations in endometrial cancer, which could be prevented by early vaccination. Our findings suggest RB1 mutations as a potential contributor to endometrial cancer in younger women, highlighting the importance of viral co-factors in risk assessments, advocating HPV vaccination in individuals with RB1 mutations.

cancer biology↗

bioRxiv2025

A role of extracellular vesicle-mediated inter-organ communication in obesity-related arrhythmia

Obesity contributes to the risk of cardiac arrhythmias, but the exact mechanism remains unclear. Here, we show visceral adipose tissue-derived extracellular vesicles (VAT EVs) from individuals with obesity prolong action potential duration (APD) and impair calcium handling in stem cell-derived cardiomyocytes, in addition to activating fibroblasts and macrophages towards a pro-fibrotic/inflammatory state, thereby creating pro-arrhythmic substrate. Adipose-derived EVs target the heart in obese mice, suggesting the potential for direct communication. Transcriptome-wide genetic association (TWAS) and epigenetic studies anchored on genes differentially expressed in cardiomyocytes, fibroblasts, and macrophages after VAT-EV exposure identified genes significantly associated with QT interval and atrial fibrillation. Finally, as a proof-of-principle, we pharmacologically blocked TRPC3 (a VAT-EV-induced ion channel) in cardiomyocytes, restoring the APD towards normality. This molecular genetic evidence supports an EV-mediated direct communication pathway between adipose tissue and the heart in arrhythmogenesis, offering a new paradigm to identify mediators of cardiovascular disease in obesity. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=192 SRC="FIGDIR/small/676027v1_ufig1.gif" ALT="Figure 1"> View larger version (74K): org.highwire.dtl.DTLVardef@114b230org.highwire.dtl.DTLVardef@1be7926org.highwire.dtl.DTLVardef@3d6b0org.highwire.dtl.DTLVardef@3ef15_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2025

Maternal exercise during lactation reprograms obesity-related changes in mammary metabolism to optimize milk fatty acids and offspring energy expenditure

Maternal obesity alters breast milk composition in ways that may predispose infants to excess adiposity. While maternal exercise during lactation has been associated with favorable shifts in milk metabolites in humans, the mechanisms by which exercise remodels the mammary gland and milk lipid profile to influence offspring metabolism remain unclear. We developed a mouse model incorporating daily moderate treadmill exercise during lactation, indirect calorimetry, stable isotope tracer respirometry, and mammary epithelial cell (MEC) proteomics in lean (LN) and diet-induced obese (OB) dams. Maternal obesity broadly remodeled the MEC proteome, reducing enzymes of de novo fatty acid synthesis and altering lipid transport and oxidative pathways. These molecular adaptations corresponded to higher milk triglyceride content and shifts in fatty acid composition, including an elevated omega-6 to omega-3 fatty acid ratio. The exercise (EX) intervention during lactation reset MEC protein networks, enhancing translational and vesicle transport pathways while reducing fatty acid desaturation, relative to the sedentary (SED) group. In OB dams, exercise increased milk medium-chain fatty acid (MCFA) levels and partially corrected the n6/n3 FA ratio. Offspring nursed by OB-EX dams exhibited higher whole-body energy expenditure, increased fatty acid oxidation, and improved metabolic flexibility compared to litters consuming OB-SED milk. Together, maternal exercise during lactation remodels mammary metabolism and milk fatty acid composition in obese dams, enhancing neonatal lipid oxidation and energy expenditure. These findings highlight lactation as a modifiable window, wherein maternal activity influences milk composition and infant metabolic health. New and noteworthyMaternal obesity alters milk fatty acid composition, with consequences for infant metabolism. Exercise during lactation in obese dams remodeled the mammary epithelial cell proteome, increasing medium-chain fatty acids in milk and enhancing lipid oxidation and energy expenditure in offspring.

physiology↗