Biology subjects

Dutta, S.

Publications and source records attributed to Dutta, S..

At least 37 records · Page 2Linked to original sources

bioRxiv2026

Small-molecule modulators of HIPK4 activity and proteostasis

Homeodomain-interacting protein kinase 4 (HIPK4) is a dual-specificity kinase that is predominantly expressed in differentiating spermatids, required for sperm development, and a promising target for nonhormonal male contraception. Genetic and functional studies have established an essential role for HIPK4 in spermiogenesis, where it acts at least in part through regulation of the F-actin-scaffolded acroplaxome during spermatid head shaping. The direct molecular targets of HIPK4 and their downstream effectors remain poorly defined, and small-molecule probes would be versatile tools for further investigating HIPK4 functions. Synthetic HIPK4 ligands could also be valuable leads for the development of nonhormonal male contraceptives. Here, we report the discovery of a cyanoquinoline-based series of HIPK4 inhibitors with nanomolar potency. Our lead compounds are selective for HIPK4, both within the HIPK family and across the broader kinome, establishing this scaffold as a useful starting point for probe and lead development. Unexpectedly, we found that a subset of these cyanoquinolines also perturbs HIPK4 proteostasis in a cell type-specific manner. In spermatids, these compounds induce the formation of detergent-insoluble HIPK4 aggregates and promote interactions between this kinase and the autophagy receptor Tax1-binding protein 1 (TAX1BP1). Together, our findings establish cyanoquinoline ligands as a new chemotype for probing HIPK4 biology and advancing male contraceptive discovery.

biochemistry↗

bioRxiv2026

AAV tools enable functional modulation and readout of central and peripheral nervous systems in spiny mice

Among mammals, spiny mice (Acomys spp.) exhibit the unique capacity to regenerate parts of their nervous system. Studying this phenomenon has the potential to reveal new targets that can slow or halt human neurodegenerative disorders. Unfortunately, research tools (e.g., transgenic lines, gene delivery vehicles) are lacking compared to those available for other rodent models. Here, we tested systemic adeno-associated viral vectors (AAVs) in Acomys dimidiatus and identified three promising candidates: X1.1, CAP-Mac, and MaCPNS1. Characterizing their tropism following intravenous delivery, we found that in the brain, MaCPNS1 and X1.1 primarily transduced astrocytes. In the peripheral nervous system, MaCPNS1 efficiently transduced dorsal root ganglia, axon bundles of the ear pinnae, and enteric neurons throughout the gastrointestinal tract. As a proof-of-concept, we used MaCPNS1 to chemogenetically modulate the activity of enteric neurons, successfully decreasing gastric motility in vivo and increasing colonic motility ex vivo. We expect these findings to enable functional studies of the uniquely regenerative nervous system of Acomys, which may in turn help advance neuroregenerative therapeutics for humans. Summary StatementIdentification of an AAV tool to efficiently deliver transgenes to the central and peripheral nervous systems of spiny mice enables functional studies of the nervous system in a mammalian model of regeneration.

neuroscience↗

bioRxiv2026

Extensive opsin gene expansion and non-cerebral origin of the minimalist eye in a model tardigrade

Panarthropod vision exhibits extraordinary morphological and functional diversity, yet the sensory biology of tardigrades--microscopic extremophiles renowned for their resilience--remains poorly understood. In the model tardigrade Hypsibius exemplaris, we uncover an unprecedented expansion of opsin genes, with over 100 paralogs constituting the largest known opsin repertoire in any animal. Paradoxically, the visual system is structurally minimalist: a paired, inverse pigment-cup ocellus embedded within the brain lobes, forming a single-pixel, dual-receptor organ. Integrating genomic, phylogenetic, molecular expression, and ultrastructural analyses, we show that directional vision relies on a single rhabdomeric opsin (He-R-Opsin-V), localized to microvilli of the rhabdomeric cell. A ciliary photoreceptor with a lamellated cilium co-expresses two ciliary opsins (He-C-Opsin-1 and -2), suggesting non-visual light detection. These and other non-visual opsins are differentially expressed in the brain, gut, storage cells, and peripheral tissues, implicating them in circadian regulation, neuromodulation, ecdysis, digestion, and environmental sensing. Crucially, the eye is an internalized epidermal vesicle, not a cerebral derivative, challenging long-standing assumptions about its evolutionary origin. These findings reveal how extreme miniaturization drives sensory system simplification in visual organs while enabling parallel evolutionary innovation in non-visual photoreception. This study establishes a new paradigm for sensory evolution in microscale animals.

zoology↗

bioRxiv2026

Neural cell state modulation by PARK2 and dopaminergic neuroprotection by small molecule Parkin agonism

Parkin, an E3 ubiquitin ligase encoded by PARK2, plays a key role in both hereditary and sporadic Parkinsons disease (PD), yet there are no therapies currently available that can target this important pathway. Here, we show that Parkin is critical for successful neuronal differentiation and survival, and we develop small-molecule Parkin agonists that can protect dopaminergic neurons. Upon differentiation of neural progenitor cells, loss of Parkin results in a reduced capacity to maintain neuronal cell state, dopaminergic neuronal phenotypes, and stress resistance. Moreover, Parkin loss disrupted cell morphology and the stability of neurites. Transcriptional and single-cell analyses reveal that Parkin controls critical pathways regulating stem-like cell transitions and is needed for stable neuronal maturation. We also examined the effects of FB231, a small molecule enhancer of Parkin E3 ligase activity, in models of PD. FB231 reduced pathological -synuclein and enhanced cell survival in human iPSC-derived dopaminergic neurons treated with -synuclein preformed fibrils. Furthermore, FB231 attenuated -synuclein pathology and dopaminergic neurodegeneration in a gut -synuclein murine model of PD. Our findings support that Parkin plays a crucial role in maintaining neuronal homeostasis and that pharmacologic activation of Parkin may be a promising strategy to attenuate neurodegeneration in PD.

neuroscience↗

bioRxiv2026

Circular Smad1-Encoded Polypeptide Regulates Myogenesis

The majority of RNAs transcribed from the genome are non-coding RNAs (ncRNAs) that are involved in regulating the expression of protein-coding genes. However, a growing body of research highlights several novel microproteins encoded by unconventional ncRNAs such as long non-coding RNAs and circular RNAs (circRNAs) as important regulators of disease and development. Although several circRNAs have recently been reported to translate into functional peptides in diverse tissues, their roles in skeletal muscle remain largely unexplored. In this study, polyribosome-associated RNA sequencing and publicly available translatable circRNAs from the riboCIRC database were curated to discover potential protein-coding circRNAs in mouse C2C12 skeletal muscle cells. We validated a few circRNAs with high potential of translating into proteins in mouse C2C12 cells, including circular Smad1 (circSmad1) that encodes a 194 amino acid peptide called circSmad1-194aa. Interestingly, silencing of circSmad1 in C2C12 cells resulted in loss of myotube fusion and maturation. CircSmad1-194aa was found to contain the DNA-binding SMAD1-MH1 domain that localized into the nucleus during myogenesis. Moreover, CircSmad1-194aa associates with the BMP-responsive element (BRE) in the Id1 promoter that is known to inhibit Myod1-driven myoblast differentiation. We propose that circSmad1-194aa promotes myogenesis by masking Id1-BRE from SMAD complex interaction, leading to suppression of ID1 expression and upregulation of MYOD1. Together, our findings identify circSmad1-194aa as a novel regulator of skeletal muscle differentiation and highlight the potential for the discovery of other functional circRNA-derived peptides in muscle pathophysiology. HIGHLIGHTSO_LIRNA-seq discovers hundreds of polysome-associated circRNAs in mouse C2C12 myoblasts C_LIO_LIProtein-coding circRNAs exhibit myogenesis-specific expression C_LIO_LICircSmad1 is abundant, methylated, and translated into a 194aa polypeptide C_LIO_LICircSmad1-encoded polypeptide promotes myogenesis C_LI GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=172 SRC="FIGDIR/small/708385v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@2074cforg.highwire.dtl.DTLVardef@d4fd98org.highwire.dtl.DTLVardef@1554735org.highwire.dtl.DTLVardef@1b6124a_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2026

Multi-Omic Analyses of Dietary Fatty Acid-Microbe-Host Interactions Reveal Metaorganismal Lipid Metabolic Crosstalk Impacting Cardiometabolic Disease

Following a meal, our gut microbiome and human cells collaborate via metaorganismal metabolic circuits to produce diverse nutrient metabolites that systemically circulate to influence health and disease. Although there are now several examples of bacterial fiber-, amino acid-, and micronutrient-derived metabolites impacting cardiometabolic disease, very little is known in regards to how diet-microbe-host interactions impact lipid homeostasis. Here we address this by defining dietary fatty acid substrate availability in germ-free versus conventionally-raised mice coupled to deep multi-omic metabolic phenotyping. Our data demonstrate that the effects of dietary saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA) on the host lipidome, transcriptome, proteome and metabolome are uniquely impacted by resident microbiota. Also, the hepatic levels of both pro-inflammatory and pro-resolving lipid mediators are strongly influenced by dietary fatty acid-microbe interactions. This study presents a unique resource to the nutrition and metabolism research community to advance our understanding of metaorganismal lipid metabolism. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC="FIGDIR/small/705588v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@4fc7e3org.highwire.dtl.DTLVardef@1cc1dc8org.highwire.dtl.DTLVardef@1b7648dorg.highwire.dtl.DTLVardef@12a8088_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGRAPHICAL ABSTRACTC_FLOATNO C_FIG

biochemistry↗

bioRxiv2025

Sleep-modulated disinhibition enables replay for memory consolidation, accelerated by ripples

Memory consolidation involves elusive neural mechanisms. Here, we develop a biophysically detailed model of the entorhinal-hippocampal-cortical network to reveal that disinhibition drives synaptic and systems consolidation. Transitioning to slow-wave sleep via neuromodulatory dampening of inhibition generates up-down states and spontaneous, time-compressed replays of spatial sequences encoded with phase precession. Lateral inhibition levels unify physiological and pathological ripple diversity. Cortical disinhibition enables memory transfer from hippocampus. Weakened afferent CA1 synapses eliminate ripples but spare replays, proposing strategies to mitigate ripple disruptions. Replays sustain systems consolidation even without ripples, albeit slower; excessive weakening halts it, rescuable by enhanced hippocampal-to-cortical connectivity. Medial entorhinal cortex (MEC)-mediated CA1 disinhibition compensates for attenuated neuromodulatory CA1 disinhibition, mimicking MEC-input-dependent quiet wakefulness replay; under this configuration during wakefulness, artificially inducing disinhibition triggers replays and ripples that drive consolidation, underscoring disinhibitions state-agnostic role. These insights elucidate disinhibitions centrality in engraining memories and fostering hippocampal independence, reconciling empirical observations, yielding testable predictions, and identifying therapeutic avenues for memory disorders.

neuroscience↗

bioRxiv2025

Tissue-Adhesive Endoscopic Tattoo Inks for Precise Marking and Surveillance of Gastrointestinal Lesions

Accurate marking of lesions and polyps is essential for effective management of gastrointestinal (GI) diseases, including colorectal cancer. Existing FDA-approved endoscopic carbon suspensions diffuse extensively within tissue and can extravasate intraperitoneally, compromising lesion localization, increasing fibrosis risk, and triggering inflammatory responses. These limitations reduce surgical precision and adversely affect patient outcomes. Here, we developed Tissue Adhesive Tattoos, generation 2 (TAT2) inks, composed of iron oxide nanoparticles encapsulated in bioadhesive polymers to improve spatial accuracy while maintaining high endoscopic contrast. TAT2 inks exhibit easy injectability, long-term stability, low macrophage inflammation, and strong spatial localization in ex vivo porcine intestinal tissue. Compared to clinical carbon ink, which spreads widely, TAT2 inks remained sharply localized with excellent contrast after submucosal injection in live mice and pigs. TAT2 also enabled visualization from both luminal and serosal surfaces and supported precise quadrant marking. Additionally, TAT2 inks were MR-compatible, expanding multimodality. Overall, TAT2 inks are biocompatible, non-inflammatory, precisely localized, and improve endoscopic marking for GI disease. TeaserEngineered bioadhesive tattoo inks deliver precise, durable GI marking with minimal spread and compatibility across imaging modalities.

bioengineering↗

bioRxiv2025

Integrated host phage RNA seq analysis of Mycobacteriophage D29 infection reveals dual arm balanced phage genome expression and inhibited expression of host transporter and VapC target genes.

The Mycobacteriophage D29 infects Mycobacterium species. Many of these are deadly human pathogens. In earlier studies, we performed proteomic analyses using a temperature-sensitive variant of D29, called D29ts12. This work indicated that a regulatory mechanism controls the expression of the phages right arm genes. In this study, we executed a transcriptomic analysis. We gained further insight into how phage infection affects gene expression, both in its genome and in the host genome. We identified several novel non-coding RNA contigs spanning the cos site junction. This finding indicates that this region is expressed. In addition, we observed two areas of intense transcriptional activity. One is located downstream of Pleft, in the right arm, and coincides with a major noncoding RNA species. This RNA species is essential for lytic growth, as reported earlier for mycobacteriophages of the A2 family. The other area of transcriptional activity was gene 17, which encodes the major coat protein. By comparing TPM values, we found that thermal inactivation of phage D29ts12 growth significantly decreased right-arm gene expression. Interestingly, an accompanying sharp increase in left-arm gene expression was observed. Therefore, a mechanism ensures balanced expression from the two arms. We also analysed the impact of phage infection on host gene expression. The results indicate significant changes in the expression levels of genes encoding transporters and genes regulated by the toxin VapC. This investigation is the first to use a mycobacteriophage to examine the combined transcriptome of the phage and its host.

microbiology↗

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

Prebiotically Plausible Peptides can Self-assemble into β-rich Nanostructures

Peptides can self-assemble into diverse morphologies in a programmable manner and hence are privileged building blocks used widely in nanotechnology. Most reported peptide nanostructures consist of one (or a few) defined sequence(s), as self-similarity is presumed to be essential for promoting assembly. While oligomerisation is seen as an important feature of the earliest functional polymers during the origin of life, prebiotic peptides were likely short, statistical, and non-templated - traits that seem incommensurate with robust self-assembly. Here we show that random 25-mer peptides can efficiently and spontaneously form highly thermostable, soluble assemblies rich with beta-sheets. Notably, these nanostructures only emerge when random peptides are constructed with an early alphabet, consisting of the 10 canonical amino acids that were also prebiotically abundant - but not other alphabets tested. Hence, our findings show that peptide self-assembly does not require purity, and in fact compositional complexity is adaptive for preventing formation of insoluble structures. Altogether, this study showcases that unevolved sequences of prebiotically-abundant amino acids can readily produce foldable self-assembling polymers, thereby providing a potential steppingstone toward the first proteins, prior to the onset of purifying selection.

biochemistry↗

bioRxiv2025

AI-assisted Image-Based Phenotyping Reveals Genetic Architecture of Pod Traits in Mungbean (Vigna radiata L.)

Mungbean (Vigna radiata (L.) R. Wilczek) is a vital source of digestible proteins and is well-suited for the plant-based protein industry. In this study, we analyzed pod morphological traits in the Iowa Mungbean Diversity (IMD) panel with 372 genotypes (2022-23) with AI-assisted image phenotyping using 2,418 pod images. Pod morphological traits were extracted using deep learning image analysis, achieving excellent agreement with manual measurements (r>0.96 for pod length and seed per pod). Four complementary GWAS models identified 45 significant SNPs associated with pod curvature, length, width, and seed per pod traits. Notably, a significant SNP (5_35265704) on chromosome 1 was linked to pod dimensional traits, length, width, and curvature. A candidate gene, Vradi01g00001116, was located within the linkage disequilibrium (LD) region of this SNP, is part of the GH3 gene family, and has an Arabidopsis ortholog (AT4G27260) known for influencing organ elongation, pod, and seed development. Another SNP, 5_210437 on chromosome 2, has been found to be significantly associated with both pod length and seed per pod. A candidate gene, Vradi02g00003971, located in the LD region of this SNP, belongs to the potassium transporter family and shares homology with the HAK5 gene family (AT4G13420) in Arabidopsis, which influences pod and seed growth. Image-based measurements achieved genomic prediction accuracies ranging from 0.61 to 0.85 across various traits, exhibiting an improvement of 12-22% over manual methods. These results demonstrate the potential of AI-assisted phenomics integrated with genomic tools to accelerate selection for improved pod architecture in mungbean breeding programs across the Midwestern United States and globally.

genomics↗

bioRxiv2025

Parkinsons disease modeling in regenerative spiny mice (Acomys dimidiatus) captures key disease-relevant behavioral, histological, and molecular signatures

Parkinsons disease (PD) is a multifactorial neurodegenerative disorder that has been modeled extensively in animals, primarily rodents, but also in non-human primates and non-mammalian organisms. However, no single animal model fully recapitulates the hallmarks of PD pathology. Here, we extend this work by modeling PD for the first time in the spiny mouse (Acomys dimidiatus), a mammal notable for its robust regeneration of multiple tissues. We show that the nigrostriatal pathway of A. dimidiatus is vulnerable to both acute 6-hydroxydopamine (6-OHDA) toxicity and chronic -synuclein (Syn) preformed fibril-induced aggregation. Mouse Syn PFFs produced widespread pS129-positive Syn inclusions across multiple brain regions, mirroring a key pathological hallmark of PD. Compared to C57BL/6J mice, A. dimidiatus exhibited more pronounced behavioral impairments, greater nigrostriatal degeneration, and higher pS129-Syn inclusion burden within substantia nigra pars compacta (SNpc) neurons. To probe the molecular underpinnings behind the vulnerability, we performed single-cell spatial proteomics, which revealed extensive proteomic alterations in dopaminergic neurons associated with Syn aggregation. Multiple proteins were dysregulated in A. dimidiatus, including those involved in proteasomal function, mitochondrial pathways, and oxidative stress regulation, which are processes commonly implicated in PD. Notably, proteomic analysis identified heightened astrocytic activation in the SNpc, which we validated histologically, suggesting a distinct glial response compared to mice. Together, these findings expand our understanding of PD-relevant pathophysiology across species and establish A. dimidiatus as a model for studying mechanisms of neurodegeneration.

neuroscience↗

bioRxiv2025

Microbial community dynamics during historic drought and flood in the Great Salt Lake

Understanding human-driven environmental impacts on microbial community distribution, abundance, and function remains a central challenge in microbial ecology. In particular, the drivers of temporal succession in community membership following perturbation remain unclear. The Great Salt Lake, Utah, bears clear hallmarks of human disturbance, including a rock-filled railroad causeway that sequestered its northern arm from freshwater river influx, leading to localized hypersalination and food web collapse. Following decades of riverine water diversion, the southern arm of this terminal lake reached a historic low elevation during a time of increased climatic change, placing strong environmental pressure on the robust saline ecosystem. Here we use molecular methods to report microbial community composition during this severe drought year at sites across the lake, including where the north and south arm waters contact. At sites of hypersaline water intrusion, we observe surprising stability in north arm community composition, in contrast with strong perturbation in south arm community structure. We use hydrodynamic modeling to pinpoint physical water flow dynamics as a key driver of these community shifts. At saturated salinity north arm sites away from hyposaline water intrusion, abundance shifts were detected in predatory and parasitic taxa, a discovery that reveals surprising ecological dynamics in saturated hypersaline systems. In sum, this study demonstrates drastic hypersaline microbial community shifts during salinity and extreme weather perturbations.

ecology↗

bioRxiv2025

HuBIE: The Human Blood Immunome Encyclopedia Of TCRs and BCRs in Bloodstream Infections and Cancer

T and B cells are central to adaptive immunity, where they identify and neutralize foreign antigens and cancer neo-antigens. Large-scale elucidation of T- and B-cell receptors (TCRs and BCRs) through immune-repertoire sequencing promises novel diagnostics, prognostic markers, and therapeutic strategies. However, progress is hampered by small cohort sizes, a lack of real-world patient diversity, and heterogeneous sample processing, impeding cross-study comparability. To overcome these limitations, here we introduce the Human Blood Immunome Encyclopedia (HuBIE), comprising immune-repertoire data from 2,614 samples collected from 1,941 participants. The cohort includes a range of bloodstream infections, several cancer types, and control participants, with many individuals providing longitudinal samples. We employed Roches immune receptor Primer Extension Target Enrichment (immunoPETE) platform to perform simultaneous targeted sequencing of T-cell receptor {beta} chains (TRB), T-cell receptor {delta} chains (TRD), and immunoglobulin heavy chains (IGH), thereby profiling TCRs and BCRs in all participants. We provide a comprehensive description of immune-repertoire diversity in cancer and bloodstream infections and examine variations across demographic variables such as age and race. We find significant differences in TRB and IGH composition across ethnic groups, and show that the fall in repertoire diversity with age follows distinct patterns for TRB, TRD, and IGH and is accompanied by age-related differences in VJ gene usage. Finally we demonstrate that greater immunological diversity is associated with improved survival but only for elderly participants. HuBIE thus constitutes a valuable resource for the immune-repertoire community, enabling large-scale mapping of the human immunome to accelerate development of diagnostics, prognostic biomarkers, and innovative therapeutic strategies.

immunology↗

bioRxiv2025

Mechanical advantage is not invoked by additional cognitive load during multi-finger dexterous object manipulation

Everyday interactions with objects depend on keeping the grasped item in static equilibrium by effectively distributing the contact forces from the fingertips. The mechanical advantage hypothesis (MAH) proposes that the central nervous system (CNS) optimises the distribution of grasping forces by favouring fingers with longer moment arms. While existing research has established that the applicability of MAH is influenced by biomechanical constraints, it remains unclear whether cognitive load, a distinct dimension of task difficulty, can similarly induce this force-sharing strategy. To investigate this, we examined whether increased cognitive demands during a multi-finger grasp- and-lift task would trigger force distribution patterns that exploit mechanical advantage. The results showed that while participants completed the task successfully, contrary to our hypothesis, the increased cognitive load did not result in a disproportionate rise in the normal force exerted by the little finger compared to the ring finger. This finding suggests that the employment of optimisation strategies like mechanical advantage may be predominantly sensitive to biomechanical rather than cognitive constraints. Significance StatementHuman grasping is a redundant control problem in that the hand has more ways to produce forces and moments than are strictly needed to achieve desired object interaction. The mechanical advantage hypothesis (MAH) is an optimisation principle proposing that the central nervous system (CNS) prefers fingers with greater leverage to address this redundancy during object manipulation. While MAH is known to emerge when mechanical difficulty increases, this study probes its boundaries and generality by asking whether nonmechanical demands also trigger it. The findings show that increased cognitive demand does not invoke MAH, highlighting that this optimisation arises primarily in response to physical and biomechanical task demands, with implications for dexterous control in rehabilitation, assistive technology, and robotics.

animal behavior and cognition↗

bioRxiv2025

A Plasmodium falciparum molecular mechanism of heme binding and sensitivity to artemisinins

Mutations in Plasmodium falciparum Kelch13 (K13) confer artemisinin resistance (ART-R) which threatens global malaria control, but known K13 functions fail to explain clinical ART-R. We reported that K13 binds the oxidant heme in vitro, however, its functions in redox-stress, cell survival and death remained unknown. Since taut control of free heme is not feasible in infected erythrocytes, we utilized a non-erythroid cell model to show that K13 directly binds and is stabilized by nanomolar heme levels. K13 also binds and regulates a major redox transcription factor, which is displaced by heme into the nucleus, to raise redox-stress responses that become suppressed during artemisinin-induced death (ART-death). K13s evolutionarily conserved kelch domain confers heme-binding and ART-death characteristics to its mammalian orthologue KEAP1. Chemical or genetic elevation of K13, fuels ART-death proportionate to K13 levels even in vast excess of heme, suggesting a novel plasmodial redox-survival mechanism licenses ART-death in clinical ART-R.

cell biology↗

bioRxiv2025

Mitigating Enterotoxigenic Escherichia coli (ETEC) infection with Probiotic and Synbiotic Treatments: A murine and in vitro study

Background & AimsEnterotoxigenic Escherichia coli (ETEC) strain H10407 is a major causative agent of Diarrhoeal diseases. This study investigates the inhibitory effects of selected probiotics (Lactobacillus casei, Lactococcus lactis, and Bifidobacterium bifidum) and their synbiotic combinations with inulin on ETEC proliferation, adhesion, intestinal colonization, and host immune response. MethodsETEC H10407 was cultured in Luria-Bertani broth and co-cultured with probiotic strains to assess growth dynamics. Adhesion and competitive inhibition assays were performed using INT 407 intestinal epithelial cells. A murine infection model (C57BL/6) was employed to evaluate pathogen colonization, diarrheal severity, stool consistency, histopathological changes, and immune modulation. Synbiotic efficacy was further tested by combining probiotics with the prebiotic inulin. Additionally, fecal microbiota transfer (FMT) was conducted to examine microbiome-mediated protective effects. ResultsProbiotic co-culture significantly inhibited ETEC growth from 2 h onward without impairing probiotic viability. All probiotics markedly reduced ETEC adhesion to INT 407 small intestinal cells. In vivo, probiotics lowered ETEC colonization by 81.34%, while synbiotics conferred an additional 29.68% reduction. Synbiotics prevent watery stool and preserve ileal architecture, with reduced goblet cell loss and neutrophil infiltration. Synbiotics significantly (p<0.0001) decreased CD3+/CD4+ Th1 cells in spleen and mesenteric lymph nodes, reduced pro-inflammatory cytokines and chemokines, and restored tight junctional proteins. ConclusionSynbiotic supplementation offered superior protection against ETEC-induced diarrhea compared to probiotics or prebiotics alone, highlighting its potential as a non-antibiotic prophylactic strategy. These findings support the role of microbiome-targeted interventions within the One Health framework to address enteric infections and antimicrobial resistance.

microbiology↗