Search bioRxiv⌕ Search

Biology subjects

Rahman, M.

Publications and source records attributed to Rahman, M..

At least 37 records · Page 2Linked to original sources

Dirt floors and domestic animals are associated with soilborne exposure to antimicrobial resistant E. coli in rural Bangladeshi households

Soil can harbor enteropathogens and antimicrobial-resistant organisms in settings with domestic animals. We enrolled 49 households with young children (28 soil floors, 21 concrete floors) in Bangladesh and recorded animal ownership/management. Staff swabbed the floor of childrens sleeping area with a sterile sponge and collected floor dust and a child hand rinse. We used IDEXX QuantiTray/2000 with and without cefotaxime supplementation to enumerate cefotaxime-resistant and generic E. coli. There was 8.0 g/m2 of dust on soil floors vs. 0.2 g/m2 on concrete floors (p-value=0.005). We detected E. coli on 100% of soil vs. 86% of concrete floors and cefotaxime-resistant E. coli on 89% of soil vs. 43% of concrete floors (p-values<0.05). Cefotaxime-resistant E. coli prevalence on floors was 36% in compounds without animals, 79% in compounds with animals and 100% if animals stayed indoors overnight or the floor had animal feces; associations were strongest for chickens. In multivariable models, generic and cefotaxime-resistant E. coli counts were 1.5-2 log higher on soil vs. concrete floors, and counts on floors and child hands were 0.17-0.24 log higher for every 10 additional chickens owned (p-values<0.05). Efforts to mitigate infections and antimicrobial resistance in low-income countries should test flooring improvements and hygienic animal management. SynopsisIn rural Bangladeshi households, generic and cefotaxime-resistant E. coli were more common on soil floors than concrete floors and among households with higher cohabitation intensity with domestic animals, especially chickens.

microbiology↗

Multiomics plasticity in seed traits of pan-genome wheat cultivars

The molecular basis of cultivar-level variations in polyploid wheat that enables environmental adaptation while maintaining yield and quality in polyploid wheat remains poorly understood. We conducted a detailed phenotypic assessment and multiomics analysis of nine pan-genome polyploid wheat cultivars grown under control and drought conditions. We aimed to investigate the subgenome-level variations, cultivar differences and biochemical mechanisms affecting plant fitness under moderate drought stress. Intrinsic water use efficiency, grain yield, and grain protein content and quality differed among cultivars, supporting the plasticity of drought stress responses. Biased proteome and metabolome abundance changes in response to moderate drought stress during the vegetative stage indicate different strategies for the utilization of homeologous protein isoforms assigned to the A, B, and D subgenomes. Drought effects were detected at the protein level, but significant changes were observed in central carbon pathway metabolites and micronutrient profiles. The subgenomic localization of seed storage proteins highlight differences in nutrient reservoir accumulation and emphasizes the enhanced role of S-rich prolamins in the stress response. Subgenomic variations define cultivar phenotypes by producing molecules that accumulate and enable the underlying trade-offs between environmental adaptation and yield- or quality-related traits. These variations can be used to select crops with increased stress resistance without compromising yield.

plant biology↗

Prefrontal cortex dopamine responds to the total valence of stimuli

The prefrontal cortex (PFC) dopamine system plays an essential role in cognitive flexibility, working memory and psychiatric disease, but determining the conditions under which dopamine in the PFC is released remains an open problem. Both rewarding and aversive stimuli have been found to trigger release, but studies have disagreed on whether the valence of a stimulus or other variables like novelty and salience are the most important. Here we report on recordings of dopamine-dependent fluorescence using a high-sensitivity dopamine indicator. We deliver an array of rewarding, aversive and mixed valence stimuli, as well as stimuli without any obvious valence. We observe that stimuli without valence, as well as the omission of expected stimuli, do not lead to large changes in fluorescence, even when these stimuli and omissions are both novel and engaging. In contrast, both rewarding and aversive stimuli lead to increases in fluorescence, with the most rewarding and most aversive stimuli leading to the largest increases. We test the effect of adding an aversive component to a rewarding stimulus and find that the increases in fluorescence are consistent with a summation of the rewarding and aversive components. We propose that dopamine release in the PFC responds to the total valence of a stimulus, in contrast with the traditional view of basal ganglia dopamine release that depends on the net valence.

neuroscience↗

Pathogens and Antimicrobial Resistance Genes in Household Environments: A Study of Soil Floors and Cow Dung in Rural Bangladesh

In low- and middle-income countries, living in homes with soil floors and animal cohabitation may expose children to fecal organisms, increasing risk of enteric and antimicrobial-resistant infections. Our objective was to understand whether cow cohabitation in homes with soil floors in rural Bangladesh contributed to the presence and diversity of potential pathogens and antimicrobial resistance genes (ARGs) in the home. In 10 randomly selected households in rural Sirajganj District, we sampled floor soil and cow dung, which is commonly used as sealant in soil floors. We extracted DNA and performed shotgun metagenomic sequencing to explore potential pathogens and ARGs in each sample type. We detected 6 potential pathogens in soil only, 49 pathogens in cow dung only, and 167 pathogens in both soil and cow dung. Pathogen species with relative abundances >5% in both soil floors and cow dung from the same households included E. coli (N=8 households), Salmonella enterica (N=6), Klebsiella pneumoniae (N=2), and Pseudomonas aeruginosa (N=1). Cow dung exhibited modestly higher pathogen genus richness compared to soil floors (Wilcoxon signed-rank test p=0.002). Using Bray-Curtis dissimilarity, pathogen species community composition differed between floors and cow dung (PERMANOVA p<0.001). All soil floors and cow dung samples contained ARGs against antibiotic classes including sulfonamides, rifamycin, aminoglycosides, lincosamides, and tetracycline. Paired floor and cow dung samples shared ARGs against rifamycin. Our findings support the development of interventions to reduce soil and animal feces exposure in rural, low-income settings. ImportanceIn low-income countries, inadequate housing materials and animal cohabitation can lead to fecal contamination of rural homes. Contaminated soil floors are difficult to clean and may harbor organisms causing illness and antibiotic resistance, especially in young children, who frequently ingest soil. We sequenced soil floor and cow dung samples from households in Sirajganj district, Bangladesh and identified pathogens and antibiotic resistance genes. We detected 167 pathogens in both soil and cow dung; pathogens present in both sample types at the highest relative abundances were E. coli, Salmonella enterica, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Antibiotic resistance genes were found in all samples. In cow dung, the most common genes conferred resistance to the antibiotics lincosamide, rifamycin, cephamycin, and tetracycline. In soil floors, the most common genes conferred resistance to rifamycin, sulfonamides, and aminoglycosides. Household soil and cow dung may be important reservoirs of pathogens and antimicrobial resistance in low-income countries.

microbiology↗

Intrinsic molecular identifiers enable robust molecular counting in single-cell sequencing

Particle-templated instant partition sequencing (PIPseq), is an emerging approach for massively scalable single-cell gene expression studies that does not require complex instrumentation or expensive consumables. We present PIPseqTM V, a novel implementation of the PIPseq workflow with significant improvements in assay performance and sensitivity compared to prior methods. Among the innovations driving the improved performance in PIPseq V is a new approach for transcript counting using Intrinsic Molecular Identifiers (IMIs) from the captured transcript sequence, eliminating the need for traditional Unique Molecular Identifiers (UMIs). IMIs are the starting positions for molecules generated by random fragmentation after limited cycle PCR, which can be used to uniquely identify individual transcript copies of genes expressed within individual cells. To correct for experimental variation in IMI generation, we have developed a dynamic correction strategy that can adapt to different sample cell input, transcript expression, and sequencing depth without the need for external benchmarking or controls. Our results demonstrate that PIPseq V with IMI-based analysis provides biological information comparable to established UMI-based approaches while avoiding UMI-associated biases. Dynamic correction offers a robust and data-driven analysis strategy for scRNAseq.

genomics↗

EnteroBase in 2025: exploring the genomic epidemiology of bacterial pathogens

This paper presents an update on the content, accessibility and analytical tools of the EnteroBase platform for web-based pathogen genome analysis. EnteroBase provides manually curated databases of genome sequence data and associated metadata from currently >1.1 million bacterial isolates, more recently including Streptococcus spp. and Mycobacterium tuberculosis. We have implemented the genome-based detection of antimicrobial resistance determinants and the new bubble plot graphical tool for visualising bacterial genomic population structures, based on pre-computed hierarchical clusters. Access to data and analysis tools is provided through an enhanced graphical user interface and a new application programming interface (RESTful API). EnteroBase is now being developed and operated by an international consortium, to accelerate the development of the platform and ensure the longevity of the resources built. EnteroBase can be accessed at https://enterobase.warwick.ac.uk as well as https://enterobase.dsmz.de. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=105 SRC="FIGDIR/small/608032v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@88ff78org.highwire.dtl.DTLVardef@3c426eorg.highwire.dtl.DTLVardef@2d8481org.highwire.dtl.DTLVardef@5644bb_HPS_FORMAT_FIGEXP M_FIG C_FIG

genomics↗

Comparative genomics reveals diversity and taxonomic relationships among Clostridioides difficile phages

Clostridioides difficile is associated with life-threatening antibiotic-associated diarrhea, colitis, and toxin-mediated infections. While antibiotics are the primary treatment against C. difficile infections, increasing resistance necessitates alternatives. Bacteriophages and bacteriophage-derived proteins such as endolysins hold promise as potential solutions. Understanding phage biology at the genomic level is crucial for their therapeutic use. We conducted a comparative genomic analysis of 44 C. difficile phage genomes from public databases, examining both whole genome and proteome levels and grouping them by shared protein content. Relationships within each group were observed, and core and highly conserved genes were identified. Using genome and proteome phylogeny, average nucleotide identity, and core gene identification, we proposed an updated taxonomic classification. Nine distinct clusters were identified, without any singleton. Cluster members exhibited similar genome architecture, genome sizes, GC content, number of coding sequences, presence of core genes, and high nucleotide identity. Additionally, we propose 23 new genera, three families and the elevation of currently assigned genera to subfamilies. The lytic module proteins, endolysins, and holins were also characterized, revealing four distinct endolysin organizations with diverse domain architectures. Notably, the amidase_3 and LysM domains were highly conserved and subjected to purifying selection within the C. difficile phage genomes. This is the first comprehensive comparative study regarding C. difficile phage genomes. Our study provides valuable genomic insights that add to the current understanding of the phages. Our taxonomic analysis may improve the classification scheme of C. difficile phages and aid in the future classification of newly isolated C. difficile phage genomes.

genomics↗

T-cell development and activation in humanized mice lacking mouse major histocompatibility complexes

Humanized mice transplanted with CD34+ hematopoietic progenitor cells (HPCs) are used to study human immune responses in vivo. However, the mismatch between the mouse major histocompatibility complexes (MHCs) and the human leukocyte antigens (HLAs) is not optimal for T-cell development and can trigger xenograft reactivity. We evaluated human T-cell development in NOD.Scid.Gamma mice lacking expression of MHC class I and II (NSG-DKO). Human leukocyte engraftment was detectable at 8 weeks post-transplantation. Human CD4+ and CD8+ T-cells were detectable in blood, thymus, bone marrow and spleen of humanized NSG-DKO mice for up to 20 weeks post-transplantation. Further, we evaluated the effects of lentiviral vector (LV) systemic delivery of HLA-A*02:01, HLA-DRB1*04:01, human GM-CSF/IFN- and the human cytomegalovirus gB antigen. LV delivery promoted development and activation of human central memory, {beta} and {gamma}{delta} T-cells with amplifications of the T-cell repertoire. LV administration unleashed multiple reactome pathways such as type-I interferon responses, cell cycle and metabolic processes. In summary, development of human T-cells in humanized mice does not rely on mouse MHCs and can be boosted systemically via LV administration.

immunology↗

TSC22D, WNK and NRBP gene families exhibit functional buffering and evolved with Metazoa for macromolecular crowd sensing

The ability to sense and respond to osmotic fluctuations is critical for the maintenance of cellular integrity. Myriad redundancies have evolved across all facets of osmosensing in metazoans, including among water and ion transporters, regulators of cellular morphology, and macromolecular crowding sensors, hampering efforts to gain a clear understanding of how cells respond to rapid water loss. In this study, we harness the power of gene co-essentiality analysis and genome-scale CRISPR-Cas9 screening to identify an unappreciated relationship between TSC22D2, WNK1 and NRBP1 in regulating cell volume homeostasis. Each of these genes have paralogs and are functionally buffered for macromolecular crowd sensing and cell volume control. Within seconds of hyperosmotic stress, TSC22D, WNK and NRBP family members physically associate into cytoplasmic biocondensates, a process that is dependent on intrinsically disordered regions (IDRs). A close examination of these protein families across metazoans reveals that TSC22D genes evolved alongside a domain in NRBPs that specifically binds to TSC22D proteins, which we have termed NbrT (NRBP binding region with TSC22D), and this co-evolution is concomitant with rapid IDR length expansion in WNK family kinases. Our study identifies functions for unrecognized components of the cell volume sensing machinery and reveals that TSC22D, WNK and NRBP genes evolved as cytoplasmic crowding sensors in metazoans to co-regulate rapid cell volume changes in response to osmolarity.

cell biology↗

Beta-cell adaptation to metabolic stresses requires prolactin receptor signaling

The role of prolactin receptor (PRLR) signaling in {beta}-cell adaptation to maternal insulin resistance of pregnancy has been well demonstrated. Using transgenic mice with an inducible {beta}-cell-specific Prlr deletion ({beta}Prlr-/-), we found that intact PRLR, as found in {beta}Prlr+/+ mice, were protected from developing glucose intolerance during pregnancy, and the main mechanism responsible for this PRLR-mediated effect is the up regulation of {beta}-cell proliferation and insulin synthesis. Interestingly, studies in male mice and humans have found a link between diminished PRLR signaling and abnormal {beta}-cell function. We aimed to determine whether PRLR has a role in regulating {beta}-cell function outside of pregnancy, protecting {beta}-cell against exposure to metabolic stressors. In this study, we found that {beta}-cell-specific PRLR reduction resulted in impaired glucose tolerance in multiparous female mice challenged with a 12-week course of high-fat diet (HFD). Unlike in pregnancy, where PRLR signaling up regulates {beta}-cell proliferation resulting in a greater {beta}-cell mass, we observed no difference in {beta}-cell mass between the wild type ({beta}Prlr+/+) and mutant ({beta}Prlr-/-) mice. In vitro glucose-stimulated insulin secretion using isolated islets from wild type ({beta}Prlr+/+) and mutant ({beta}Prlr-/-) mice showed comparable insulin response, but {beta}Prlr-/- mice showed blunted first-phase insulin release in vivo, although only when challenged with glucose orally and not intraperitoneally, suggesting an impairment of the incretin effect. In support of the observed defect in incretin action, we found a reduction in expression of both incretin hormone receptors, Gipr and Glp-1r, and several of their upstream regulators, such as E2f1, Nkx6.1, Pax6, Ppar{gamma}, and Tcf7l2. Islets from the mutant mice also have a lower insulin content and reduced levels of genes that regulate glucose metabolism. Together, these results suggested that PRLR signaling plays an important role in preserving {beta}-cell function in mice exposed to metabolic stress by maintaining incretin receptor expression and insulin secretory capacity in {beta} cells.

physiology↗

Systemic Dosing of Virus-derived Serpin Improves Survival and Immunothrombotic Damage in Murine Colitis

Inflammatory bowel disease (IBD) is potentially life-threatening, with risk of bleeding, clotting, infection, sepsis, cancer and toxic megacolon. Systemic and local immune and coagulation dysfunction increase IBD severity. Current treatments are partially effective, but there is no definitive cure. Serine protease cascades activate thrombotic, thrombolytic and complement pathways and are regulated by inhibitors, serpins. Viruses encode proteins evolved from endogenous central regulatory pathways. A purified secreted Myxomavirus-derived serpin, Serp-1, dosed as a systemic anti-inflammatory drug, has proven efficacy in vascular and inflammatory disorders. PEGylated Serp-1 protein (PEGSerp-1) has improved efficacy in lupus and SARS-CoV-2 models. We examined PEGSerp-1 treatment in a mouse Dextran Sodium Sulfate (DSS) colitis model. Prophylactic PEGSerp-1 significantly improved survival in acute severe 4-5% DSS colitis, reducing inflammation and crypt damage in acute 4-5% DSS induced colitis and when dosed as a chronic delayed treatment for recurrent 2% DSS colitis. PEGSerp-1 reduced iNOS+ M1 macrophage invasion, damage to crypt architecture and vascular inflammation with decreased uPAR, fXa, fibrinogen and complement activation. This work supports PEGSerp-1 as a tissue targeting serpin therapeutic.

molecular biology↗

A Hypothalamic Circuit Underlying the Dynamic Control of Social Homeostasis

Social grouping increases survival in many species, including humans1,2. By contrast, social isolation generates an aversive state (loneliness) that motivates social seeking and heightens social interaction upon reunion3-5. The observed rebound in social interaction triggered by isolation suggests a homeostatic process underlying the control of social drive, similar to that observed for physiological needs such as hunger, thirst or sleep3,6. In this study, we assessed social responses in multiple mouse strains and identified the FVB/NJ line as exquisitely sensitive to social isolation. Using FVB/NJ mice, we uncovered two previously uncharacterized neuronal populations in the hypothalamic preoptic nucleus that are activated during social isolation and social rebound and that orchestrate the behavior display of social need and social satiety, respectively. We identified direct connectivity between these two populations of opposite function and with brain areas associated with social behavior, emotional state, reward, and physiological needs, and showed that animals require touch to assess the presence of others and fulfill their social need, thus revealing a brain-wide neural system underlying social homeostasis. These findings offer mechanistic insight into the nature and function of circuits controlling instinctive social need and for the understanding of healthy and diseased brain states associated with social context.

neuroscience↗

mRNA challenge predicts brain cancer immunogenicity and response to checkpoint inhibitors

To prospectively determine whether brain tumors will respond to immune checkpoint inhibitors (ICIs), we developed a novel mRNA vaccine as a viral mimic to elucidate cytokine release from brain cancer cells in vitro. Our results indicate that cytokine signatures following mRNA challenge differ substantially from ICI responsive versus non-responsive murine tumors. These findings allow for creation of a diagnostic assay to quickly assess brain tumor immunogenicity, allowing for informed treatment with ICI or lack thereof in poorly immunogenic settings.

cancer biology↗

Computational investigation of Scutellarein derivatives as an inhibitor against triple-negative breast cancer by Quantum calculation, and drug-designed approaches

Triple-negative breast cancer accounts for 10-15% of all breast tumors (TNBC). Triple-negative breast cancer lacks either estrogen or progesterone receptors (ER or PR), producing either too little or too much HER2. (All three tests result in "negative" results for the cells.) These cancers are more common in women under 40 who are Black or have the BRCA1 mutation. TNBC differs from other types of invasive breast cancer in that it has fewer treatment options, a worse prognosis, and grows and spreads more quickly (outcome). So, first of all, the protein of triple-negative breast cancer was collected from the PDB database having the most stable configuration, and a natural bioactive molecule, Scutellarein, was selected. Scutellarein is well-known to possess anti-cancer properties, so its derivatives were chosen to design anticancer drugs through computational tools. In this case, the functional group has applied and modified structural activity relationship methods. Then, the pass prediction score was taken, which indicates the probability of active (Pa) and the probability of inactive (Pi). After that, other in-silco approaches, such as the ADMET parameter, and quantum calculation by Density Functional Theory (DFT), have been conducted. Finally, molecular docking and dynamics have been evaluated against TNBC to determine the binding affinity and stability. Scutellarein derivatives (DM03 at -10.7 kcal/mol, DM04 at -11.0 kcal/mol) have been reported to have a maximum tendency for binding against TNBC. Besides, the molecular dynamic simulation was performed at 100ns and described by root-mean-square deviation (RMSD) and root-mean-square fluctuation (RMSF), which are much more stable compounds. The pharmacokinetics specifications for a suitable therapeutic candidate were satisfied by these molecules, like as non-carcinogenic, minimal to aquatic and non-aquatic toxicity. Almost all the molecules are highly soluble in the aqueous system. These all-computational data suggested that they might be suitable as a medication for the inhibition of TNBC, and further experimental studies should be carried out.

bioinformatics↗

Dimensionality reduction methods for extracting functional networks from large-scale CRISPR screens

CRISPR-Cas9 screens facilitate the discovery of gene functional relationships and phenotype-specific dependencies. The Cancer Dependency Map (DepMap) is the largest compendium of whole-genome CRISPR screens aimed at identifying cancer-specific genetic dependencies across human cell lines. A mitochondria-associated bias has been previously reported to mask signals for genes involved in other functions, and thus, methods for normalizing this dominant signal to improve co-essentiality networks are of interest. In this study, we explore three unsupervised dimensionality reduction methods - autoencoders, robust, and classical principal component analyses (PCA) - for normalizing the DepMap to improve functional networks extracted from these data. We propose a novel "onion" normalization technique to combine several normalized data layers into a single network. Benchmarking analyses reveal that robust PCA combined with onion normalization outperforms existing methods for normalizing the DepMap. Our work demonstrates the value of removing low-dimensional signals from the DepMap before constructing functional gene networks and provides generalizable dimensionality reduction-based normalization tools.

bioinformatics↗

Treatment with anti-inflammatory viral serpin modulates immuno-thrombotic responses and improves outcomes in SARS-CoV-2 infected mice

1.Severe acute respiratory distress syndrome (ARDS) during SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2) infection, manifests as uncontrolled lung inflammation and systemic thrombosis with high mortality. Anti-viral drugs and monoclonal antibodies can reduce COVID-19 severity if administered in the early viremic phase, but treatments for later stage immuno-thrombotic syndrome and long COVID are limited. Serine protease inhibitors (SERPINS) regulate activated proteases during thrombotic, thrombolytic and immune responses. The myxoma poxvirus-derived Serp-1 protein is a secreted immunomodulatory serpin that targets activated coagulation and complement protease pathways as part of a self-defense strategy to combat viral clearance by the innate immune system. When purified and utilized as an anti-immune therapeutic, Serp-1 is effective as an anti-inflammatory drug in multiple animal models of inflammatory lung disease and vasculitis. Here, we describe systemic treatment with purified PEGylated Serp-1 (PEGSerp-1) as a therapy for immuno-thrombotic complications during ARDS. Treatment with PEGSerp-1 in two distinct mouse-adapted SARS-CoV-2 models in C57Bl/6 and BALB/c mice reduced lung and heart inflammation, with improved clinical outcomes. PEGSerp-1 significantly reduced M1 macrophage invasion in the lung and heart by modifying urokinase-type plasminogen activator receptor (uPAR) and complement membrane attack complex (MAC). Sequential changes in urokinase-type plasminogen activator receptor (uPAR) and serpin gene expression were observed in lung and heart with PEGSerp-1 treatment. PEGSerp-1 is a highly effective immune-modulator with therapeutic potential for treatment of severe viral ARDS with additional potential to reduce late SARS-CoV-2 complications related to immune-thrombotic events that persist during long COVID. SignificanceSevere acute respiratory distress syndrome (ARDS) in SARS-CoV-2 infection manifests as uncontrolled tissue inflammation and systemic thrombosis with high mortality. Anti-viral drugs and monoclonal antibodies reduce COVID-19 severity if administered early, but treatments for later stage immuno-thrombosis are limited. Serine protease inhibitors (SERPINS) regulate thrombotic, thrombolytic and complement pathways. We investigate here systemic treatment with purified poxvirus-derived PEGSerp-1 as a therapeutic for immuno-thrombotic complications in viral ARDS. PEGSerp-1 treatment in two mouse-adapted SARS-CoV-2 models (C57Bl/6 and BALB/c) significantly reduced lung and heart inflammation and improved clinical outcomes, with sequential changes in thrombolytic (uPAR) and complement expression. PEGSerp-1 is a highly effective immune-modulator with therapeutic potential for immune-thrombotic complications in severe viral ARDS and has potential benefit for long COVID.

microbiology↗

The Na+/K+ pump dominates control of glycolysis in hippocampal dentate granule cells

Cellular ATP that is consumed to perform energetically expensive tasks must be replenished by new ATP through the activation of metabolism. Neuronal stimulation, an energetically demanding process, transiently activates aerobic glycolysis, but the precise mechanism underlying this glycolysis activation has not been determined. We previously showed that neuronal glycolysis is correlated with Ca2+ influx, but is not activated by feedforward Ca2+ signaling (Diaz-Garcia, Meyer, et al., 2021). Since ATP-powered Na+ and Ca2+ pumping activities are increased following stimulation to restore ion gradients and are estimated to consume most neuronal ATP, we aimed to determine if they are coupled to neuronal glycolysis activation. By using two-photon imaging of fluorescent biosensors and dyes in dentate granule cell somas of acute mouse hippocampal slices, we observed that production of cytoplasmic NADH, a byproduct of glycolysis, is strongly coupled to changes in intracellular Na+, while intracellular Ca2+ could only increase NADH production if both forward Na+/Ca2+ exchange and Na+/K+ pump activity were intact. Additionally, antidromic stimulation-induced intracellular [Na+] increases were reduced >50% by blocking Ca2+ entry. These results indicate that neuronal glycolysis activation is predominantly a response to an increase in activity of the Na+/K+ pump, which is strongly potentiated by Na+ influx through the Na+/Ca2+ exchanger during extrusion of Ca2+ following stimulation.

neuroscience↗

Mitochondrial TFAM in the Regulation of FOXP3+ T cell Mediated Maintenance of CD4+ T Cell Landscapes

Foxp3 regulatory T cells (Tregs) maintain immune homeostasis, yet the process that preserves their stability during aging remain unclear. Mechanistic progress has been hindered by models that ablate Tregs or delete Foxp3, which induce acute autoimmunity and prevent longitudinal study of physiological regulatory drift. Here, we establish a dose-dependent mitochondrial framework that preserves Treg lineage survival while permitting gradual metabolic attenuation. Using Treg-restricted TFAM modulation, a complementary haploinsufficient model, and whole-spleen single-cell profiling. We identify lineage-selective immune remodeling characterized by contraction of naive CD8 and follicular B-cell pools, alteration of CD4 states, expansion of activated Tregs, and emergence of neuroimmune stress linked transcriptional modules that parallel physiological aging. Mechanistically, mitochondrial insufficiency is associated with functional loss of FOXP3-centered chromatin coordination and enrichment of NF-{kappa}B/NFAT/AP-1 inflammatory and senescence programs while lineage identity remains detectable. Partial mitochondrial attenuation within Tregs alone is sufficient to drive chronic low-grade systemic inflammation, neuromuscular decline, gut microbial restructuring, and elevated microglial responsiveness without Treg depletion. Pharmacologic and microbiota-directed interventions partially reduce inflammatory tone and improve functional metrics. Together, our findings identify TFAM as a key regulator of immune aging and reveal that healthy mitochondrial function in Tregs is essential for protecting against inflammaging and age-associated functional decline.

immunology↗