Science Advances

Early life nutrition profoundly influences long-term metabolic health, and breast milk not only provides nutrients but also conveys maternal signals shaping infant metabolic development. While postpartum exercise by lactating women benefits maternal health, its impact on milk-borne signaling remains largely undefined. Small extracellular vesicles (sEVs) in breast milk are key mediators of maternal to infant communication because of their selectively packaged bioactive cargo and resistance to infant digestive enzymes and acids, enabling delivery of their cargo to peripheral tissues. Here, we show that a single session of moderate-intensity postpartum aerobic exercise robustly increases human breast milk sEV concentration, which persists for multiple post-exercise milk collections. Exercise enriches breast milk with sEVs containing regulatory metabolic cargo (proteins, miRNAs, and metabolites), which translates into enhanced mitochondrial capacity in neonatal stage cells. These findings implicate sEVs as an exercise-responsive signaling compartment in breast milk capable of connecting postpartum maternal physical activity to beneficial infant metabolic programming.

The opioid crisis has emphasized the need for more effective treatments for opioid use disorder (OUD)1-3, which is characterized by habitual opioid use to avoid withdrawal symptoms4,5. Both physical and affective symptoms contribute to opioid withdrawal yet whether different neural mechanisms mediate these different symptom domains and contribute distinctly to opioid relapse is unknown. While neurons expressing mu opioid receptors (MORs) gate opioids reinforcing effects6-8 by increasing dopamine (DA) release in nucleus accumbens (NAc), sharp decreases in NAc DA release are associated with withdrawal9-11, the cellular and circuit mechanisms of which are unknown. Here we describe an unusual population of evolutionarily-conserved MOR+ neurons in the NAc expressing the transcription factor Tshz1. Increased activity in these neurons is required for withdrawal aversion learning. Deletion of MORs in Tshz1 neurons prevented withdrawal-induced decreases in DA release and affective aversion, but not physical symptoms associated with withdrawal. Pharmacological activation of mGluR8, which is preferentially expressed in Tshz1 neurons, reduced withdrawal aversion. Thus, by dissociating the circuit mechanisms contributing to the physical and affective components of opioid withdrawal focusing on the critical role of Tshz1 neurons, we have identified a novel druggable target with therapeutic potential for treating key OUD withdrawal symptoms.

Menopause affects over one billion women worldwide, yet remains poorly characterized at scale. We apply an ICD-10-based phenotyping algorithm to electronic health records (EHR) from an academic medical center (n=33,444 women aged 35-64) and a safety-net hospital system (n=7,041), yielding one of the most racially and socioeconomically diverse menopause cohorts in the literature. Structured EHR fields underrepresent symptom burden: only 38.8% of patients had any documented symptom via natural language processing, despite an estimated prevalence of 90%. Adverse pregnancy outcomes were associated with earlier menopause onset after adjustment ({beta}=-1.21 years, p=8.7x10-45). Menopausal women showed elevated risk for osteoporosis (hazard ratio of 12.40), rheumatoid arthritis (HR of 2.43), and mental and behavioral disorders (HR 2.38) relative to age-matched men, with divergence at menopause onset. We show that large-scale EHR can characterize menopause at a scale and diversity that prospective enrollment has not achieved.

People do not always feel as they appear. Someone who seems stable may struggle internally, whereas someone who appears distressed may experience it differently. This gap matters in psychiatry, where assessment relies on symptom scales and external evaluation. Here we developed mindGAP (Measuring INDividual-population GAPs in psychiatric energy landscapes), a hierarchical variational Bayesian framework that uses longitudinal questionnaire data to estimate both population-level symptom dynamics and each participants individual symptom dynamics. We applied mindGAP to time-series PHQ-9 data from 248 participants during the COVID-19 pandemic. The population landscape contained three major states, whereas individualized landscapes often diverged from this shared structure. We quantified this gap as individual-population landscape divergence, which was associated not only with depressive severity but also with modern-type depression-related traits (TACS-22) and interpersonal sensitivity-self traits (IPS-22). Thus, mindGAP opens a route to quantifying a previously unquantified gap between population-level and individual-level symptom organization.

Mammalian diet and feeding ecology are often reflected by craniofacial skeleton specializations, but feeding requires skeletal actuation by a complex suite of muscles with varying sizes, lines of action, and mechanical function. While muscles play a critical role in feeding mechanics, and hence diet, it remains unclear how well variation in jaw muscle morphology predicts diet in mammals. We quantified the evolutionary interplay between mammalian muscle morphology and diet using a large and taxonomically broad sample. We measured the relative proportions and putative force production capacity, quantified as muscle physiological cross-sectional area (PCSA), for the major adductor complexes, along with a key jaw depressor, in 91 mammalian species (30 chiropterans, 33 primates, and 28 ungulates, carnivorans, rodents, and marsupials). We recovered clear dietary signals for several muscle complexes, with the medial pterygoid (larger in herbivores) and temporalis (larger in carnivores) performing best as dietary predictors. The medial pterygoid is particularly relevant for the mechanical innovation in mammals of moving the mandible along non-orthal, medio-lateral trajectories during mastication. Our findings underscore the intuitive, yet previously unquantified, importance of muscles in the evolution of mandibular roll, yaw, and lateral translation, all mammalian hallmarks of processing diverse types of food.

The RNA helicase MOV10 is highly expressed in developing brain, is present in synapses and is required for embryonic viability. A murine brain-specific knockout of MOV10 (Mov10 Deletion) has a thickened cortex, abnormal dendritic arborization and enhanced fear memory. In human studies, MOV10 is among the loci that is correlated with enhanced cortical brain volumes and is also significantly associated with substance dependence by epigenetic profiling. Here we demonstrate that Mov10 Deletion mice show enhanced fear learning that is aligned with impaired structural connectivity of canonical fear circuits revealed by Diffusion Tensor Imaging. We propose a model where MOV10 loss leads to increased GABRA2 expression in the hippocampus and reduced anatomical connectivity that drives augmented fear learning. Memory reactivation is observable during fear memory retrieval as an overall increase in fMRI functional activity in cortical regions. Taken together, this framework identifies that enhanced fear in the MOV10 model is driven via a "corticalized" fear response during re-exposure to the training context that is not driven by the canonical fear circuit. These findings support a molecular basis for non-traditional enhanced learning mechanisms activated by fearful events that shed light on the intractability of fear memories with the potential to inform PTSD and substance dependence disorders.

Plants, as sessile organisms, must continually adapt to fluctuating temperatures to ensure survival. The plasma membrane-localized receptor-like kinase FERONIA (FER) coordinates diverse physiological processes and responses to various biotic and abiotic stresses. However, the role of FER in plant adaptation to elevated temperatures remains largely unexplored. Here, we report that FER is indispensable for plant thermotolerance. We found that fer loss-of-function mutants exhibit impaired thermomorphogenic growth and are hypersensitive to mild heat stress, displaying extensive oxidative stress-mediated cell death at elevated temperatures. Combined genetic and molecular analyses revealed that these temperature-sensitive defects in fer mutants are caused by an overaccumulation of jasmonic acid (JA), which subsequently triggers excessive production of reactive oxygen species. Furthermore, we show that this aberrant JA accumulation and oxidative stress are attributable to impaired FER-mediated regulation of turgor-dependent cell wall tensile stress. Taken together, our results suggest that FER-mediated cell wall tensile stress regulation serves as a critical mechanism to prevent aberrant JA accumulation and oxidative stress at elevated temperatures, thereby enabling plants to adapt to and survive under high-temperature conditions.

In ants and other eusocial insects, reproductive division of labor is tightly regulated by juvenile hormone (JH), which suppresses reproduction in most individuals to maintain the worker caste. However, how social cues trigger systemic JH suppression to permit reproductive activation remains unclear. In the ant Harpegnathos saltator, workers respond to queen loss by engaging in sustained ritualistic dueling and transitioning into reproductive, long-lived pseudoqueens (gamergates). This provides a powerful model for investigating the molecular basis of socially induced plasticity. We examined the hemolymph proteome of transitioning ants and identified HCRG1, a lineage-restricted peptide upregulated during dueling, as a circulating factor that physically interacts with Hex70c, a broadly conserved JH-binding Hexamerin. HCRG1 promotes ovarian development by antagonizing JH signaling. Expression of ant HCRG1 in the heterologous solitary model Drosophila also extends lifespan. These findings identify an evolutionarily derived circulating factor that links social sensory perception to systemic JH suppression, enabling coordinated reproductive and longevity transitions in a social insect.

Mitochondrial density in dendrites adapts to the number of synaptic inputs to adequately sustain local ATP and Ca2+ buffering for neuronal signaling. During long-term depression (LTD), synapse elimination is accompanied by activation of caspase-3 through sublethal mitochondria-derived apoptotic signals, driving neurotransmitter receptor internalization and spine shrinking. However, the upstream signals that link synaptic activity to mitochondrial remodeling remain unknown. Here we show that Na+ influx through NMDA receptors depolarizes mitochondria during chemically induced LTD. This triggers stabilization and activation of the PINK1 kinase in a translation-dependent manner, leading to asynchronous mitochondrial fission. Na+ influx and PINK1 are required for cLTD-induced fission, and blocking either Na+ influx or PINK1 prevents caspase-3 activation and spine shrinking in cultured neurons. Together, these findings identify a Na+-PINK1 signaling axis that couples NMDA receptor activity to mitochondrial fission and caspase-3-dependent synapse elimination during LTD, with implications for the homeostatic regulation of synaptic density.

Chondrocyte-based cartilage repair strategies such as autologous chondrocyte implantation (ACI) require extensive in vitro expansion to obtain clinically relevant cell numbers. However, this expansion step progressively drives chondrocyte dedifferentiation, reducing matrix-forming capacity and contributing to variable repair outcomes. To better understand this process, we used single-nucleus multiome profiling (snRNA-Seq + snATAC-Seq) to define the transcriptional and chromatin accessibility programs underlying human chondrocyte dedifferentiation during expansion. Multiome integration across passages revealed a continuous dedifferentiation trajectory accompanied by coordinated remodeling of gene expression and chromatin accessibility, identifying chromatin destabilization as an early regulatory event during phenotype loss. Guided by these regulatory signatures, we screened available small-molecule inhibitors targeting candidate pathways and found that Fludarabine most consistently preserved chondrocyte identity during early expansion. Fludarabine was associated with suppression of STAT1-related programs and early stabilization of the chromatin landscape prior to broader transcriptional recovery. Functionally, treated cells demonstrated enhanced matrix-forming capacity in chondrogenic pellet culture and significantly increased nascent protein synthesis in 3D hydrogel culture, with biosynthetic output approaching unexpanded controls by day 21. Together, these findings identify chromatin stability as a key regulatory determinant of expansion-associated chondrocyte dedifferentiation and establish a pharmacologic strategy to preserve chondrocyte functional potency during cell manufacturing for cartilage repair.

Cardiac contraction depends on synchronized interactions between myosin-based thick filaments and actin-based thin filaments (TFs). Precise regulation of TFs length is vital for cardiac function, as any alteration in length leads to severe myopathies. Actin filaments form the backbone of the TF and have two unequal ends - fast-growing barbed and slow-growing pointed. In muscle, the barbed end is capped at the Z-line, while the pointed end is regulated by the tropomodulin family of proteins. Tropomodulin caps the pointed end, while leiomodin-2 (Lmod2) promotes actin nucleation and pointed end elongation. Lmod2 has a unique C-terminal extension (CTE) that is important for actin nucleation and binds to the sides of matured TFs. The structural mechanism by which Lmod2 promotes elongation remains elusive. We employed cryo-electron microscopy to visualize the structure of growing pointed ends nucleated by Lmod2 from profilactin. We show that Lmod2s leucine-rich repeat domain (LRR) stabilizes terminal actin subunits by binding across the helical groove of actin. We identified two distinct populations of pointed-end LRR-containing complexes on one or both actin strands. LRR binding pushes the terminal actins outward from their ideal positions in the actin filament, introducing strain at the pointed end that squeezes LRR from the filaments exterior. We also show that the Lmod2 CTE may stabilize Lmod2 binding to the pointed end. We suggest that Lmod2 promotes the addition of new actins to the pointed end but is expelled from the growing filament, thereby maintaining the concentration of Lmod2 required for further elongation.

Repairing damaged tissues is essential for the survival of all organisms. In plants, tissue injury rapidly triggers defense and repair programs. However, the molecular mechanisms linking early injury cue to the later stages of wound repair remain unclear. Here, we show that wounding of Arabidopsis leaves induces localized low temperature at the injury site, likely caused by evaporative cooling, which is accompanied by an activation of cold-responsive genes. Using thermal imaging combined with computer vision and deep learning, we developed a workflow to monitor the dynamics of wound healing in a quantitative, non-invasive and real-time manner. Mechanistically, we show that C-repeat Binding Factor (CBF) transcription factors are required for the activation of injury-associated cold response and downstream salicylic acid (SA) signaling. The CBF-SA module promotes lignin deposition and wound repair. Together, these findings reveal a link between a wound-induced biophysical cue and the tissue repair program.

Cholinergic, dopaminergic and serotonergic neuromodulation has pervasive effects on circuit functions in prefrontal cortex (PFC) and striatum and interact with glutamatergic and GABAergic transmission. But how these neurochemicals interact during cognitive engagement is largely unknown and inferred from studying few neuromodulators at a time. Here, we sampled the extracellular availabilities of five neurochemicals in the PFC and striatum of nonhuman primates and tested how they changed when subjects switched from rest to engage in a cognitive set shifting task using miniaturized probes for diffusion-based solid-phase microextraction. Cognitive engagement was best predicted by GABAergic and cholinergic changes in the PFC, and dopaminergic and cholinergic changes in the striatum. Glutamate co-modulated with acetylcholine across states in both the PFC and striatum, while serotonin changes in PFC and striatum correlated consistent with common external modulation. These findings document an area-specific multi-neuromodulatory fingerprint of an adaptive cognitive state in the fronto-striatal network of the nonhuman primate brain. TeaserEngaging in a cognitive task reshapes neurochemical profiles across the fronto-striatal network of the primate brain

Dopaminergic neurons in the substantia nigra depend on iron for dopamine synthesis but are vulnerable to iron-induced oxidative stress. Many of these neurons synthesize neuromelanin, an iron-chelating pigment that accumulates across the lifespan and makes them vulnerable in Parkinsons disease. It remains unclear whether their selective vulnerability arises from neuromelanin overload or from the release of toxic labile iron from the oversaturated pigment. We quantified iron and neuromelanin at the single-cell level across the lifespan of chimpanzees, a species closely resembling humans in pigment and iron accumulation. Combining quantitative MRI, X-ray fluorescence imaging, and microscopic colorimetry, we found that the iron-to-neuromelanin ratio remains stable with age across large neuronal populations. Chemical equilibrium modeling of the iron binding in neuromelanin indicated that cytosolic labile iron concentrations remain low throughout adulthood. We have found no evidence for neuromelanin saturation or increased iron-mediated toxicity with age. This finding challenges the hypothesis that neuromelanin saturation drives age-related dopaminergic vulnerability. The presented method provides a quantitative framework for studying iron homeostasis in these neurons.

How did phosphate become the universal energetic currency of life? Traditional approaches to phosphorylation in early evolution studies entail oven drying, non-aqueous solvents, dangerously reactive forms of phosphorus, or other non-physiological conditions. With microbial physiology as a vade mecum, we have recently found that phosphite, HPO32-, which is enzymatically oxidized by many microbes and which naturally occurs in serpentinizing hydrothermal vents, will readily phosphorylate ribose, glucose, glycerol, serine, AMP, creatine and acetate to generate phosphoester, phosphoanhydride and acylphosphate bonds in hours to days at 25-100{degrees}C in pure alkaline water. These reactions are thermodynamically favourable because anoxic phosphite oxidation to phosphate and H2 is highly exergonic, but they do not proceed without catalysts. The most effective catalyst yet identified is a nanoparticular form of a shiny metal: zero-valent (native, or elemental) palladium (Pd0). Native palladium, like phosphite, also naturally occurs in serpentinizing hydrothermal vents, as do other native platinum group elements (PGE), including Pt, Rh, Ru and Ir. Here we test those PGE as catalysts of phosphite oxidation and phosphorylation. Though all metals tested readily oxidize phosphite, only Pd0 efficiently catalyzes phosphorylation, generating phosphorylated products at concentrations often equal to their physiological concentrations in growing Escherichia coli cells. Metaphosphate is a possible reaction intermediate. In phosphorylation reactions via phosphite oxidation (DG0'= -46 kJ{middle dot}mol-1), a portion of the energy released is conserved in phosphorylated products, as in biological energy conservation. A natural environment and energy-conserving thermodynamics implicate these facile aqueous phosphorylating reactions in the origin of bioenergetics.

TRPV1 (transient receptor potential vanilloid 1) is a non-selective cation channel with high permeability to Ca2+ and is best known for its roles in sensory signaling. However, its function in immune cell biology, particularly in macrophage fusion, remains unknown. Cell fusion is a critical process in both physiological and pathological contexts, including development, tissue remodeling, and the foreign body response (FBR) to implanted biomaterials. During FBR, macrophages undergo fusion to form multinucleated foreign body giant cells (FBGCs), which contribute to implant degradation and fibrotic encapsulation. Here, we identify TRPV1 as a key regulator of macrophage multinucleation and FBGC formation. We demonstrate that TRPV1 is endogenously expressed in bone marrow-derived macrophages (BMDMs) and is upregulated in response to fusogenic cytokines and inflammatory stimuli. Functionally, TRPV1 promotes matrix stiffness-dependent macrophage adhesion and spreading, indicating a role in mechanosensitive signaling. We show that TRPV1 is required for efficient macrophage fusion under both cytokine-driven and matrix stiffness-mediated conditions. Mechanistically, TRPV1 links extracellular mechanical cues and cytokine signaling to cytoskeletal remodeling, facilitating the actin reorganization necessary for cell fusion. Importantly, TRPV1 deficiency does not alter TRPV4-mediated Ca2+ signaling, demonstrating that TRPV1 operates independently of TRPV4, a known mechanosensitive channel implicated in FBR and FBGC formation. Collectively, these findings suggest TRPV1 as a previously unrecognized mechanosensitive regulator of macrophage fusion and FBGC formation. This work provides new insight into the molecular mechanisms governing FBR and identifies TRPV1 as a potential therapeutic target for improving biomaterial biocompatibility and mitigating fibrosis.

Calcium signalling and structural roles are fundamental for plant growth, development, and environmental adaptation. Recent studies have identified MILDEW RESISTANCE LOCUS O (MLO) proteins as novel calcium-permeable channels with roles in root growth, cell wall development, pollen tube growth, and perception. However, the molecular mechanisms underlying MLO function remain unknown. Here, we demonstrate that multimerisation is essential for MLO activity. Chemical crosslinking, split-ubiquitin interaction assays, and single-molecule photobleaching revealed that MLO proteins form stable dimeric and trimeric assemblies at the plasma membrane. Structural modelling uncovered a molecular architecture of the MLO trimer with a central ion-conducting pore, which was further examined by molecular dynamics simulations in a lipid membrane environment. Computational electrophysiology showed preferential inward Ca2+ transport, confirming that MLO proteins function as calcium influx transporters, and identified a conserved set of pore-lining residues that coordinate ion translocation. Functional and structural analyses indicated that the mechanism of calcium permeation is evolutionarily conserved. Our findings provide mechanistic insight into MLO-mediated calcium influx across the plasma membrane and establish multimerisation as a critical determinant of this calcium channels activity.

-Lipoic acid (LA) is widely included in "mitochondrial cocktails" recommended to patients with primary mitochondrial disorders, yet its mechanism of action remains unclear. Here, we define the intracellular availability and functional utilization of LA in mammalian cells. We show that LA exists in two functionally distinct cellular pools: a low-abundance free pool and a protein-bound pool generated through mitochondrial fatty acid synthesis (mtFAS). Disruption of the mtFAS pathway abolishes protein lipoylation and impairs oxidative phosphorylation without altering free LA levels. Conversely, supplementation with exogenous LA markedly increases free intracellular LA without restoring protein lipoylation, mitochondrial respiration, or cell proliferation. Instead, the cellular effects of LA supplementation resemble those of the antioxidant N-acetylcysteine. These findings clarify the mechanism of action of a widely used mitochondrial supplement and identify a fundamental disconnect between cellular LA abundance and mitochondrial utilization, challenging the rationale for using LA supplementation to restore mitochondrial function.

Serotonins role in motivated behaviour remains unresolved due to a lack of causal, spatially precise, and translatable methods. Here, we introduce ultrasound-mediated neuromodulator delivery to achieve focal, non-invasive access to the primate brain by transiently opening the blood-brain barrier, enabling systemically administered serotonin to reach a targeted cortical region. We delivered serotonin to the perigenual anterior cingulate cortex (pgACC) of awake, behaving macaques and combined this with computational modelling and multimodal imaging, including resting-state fMRI and single-voxel MRS. Elevating pgACC serotonin reduced occupancy of high-motivation states by weakening the energizing influence of rich reward environments, while leaving sensitivity to immediate offer value intact. This was accompanied by altered frontal functional connectivity, reduced local glutamatergic metabolite signal, and changes in pupil-linked physiology. Repeated delivery was well tolerated, and histology confirmed increased serotonergic signal at the target. These findings establish a translatable approach for focal neuropharmacological manipulation and identify pgACC serotonin as a regulator of context-dependent motivation.

Bone remodeling is a tightly regulated physiological process that maintains bone health through coordinated action of bone-resorbing osteoclasts and bone-forming osteoblasts. Disruption of this balance, such as the one induced by estrogen decline after menopause, results in bone loss and osteoporosis. Genetic factors play an important role in determining bone mineral density (BMD) loss over time. However, translating genetic associations into individualized risk prediction remains challenging due to small effect size of individuals variants and non-linear interactions within the bone remodeling unit. Here, we present a bone cell population dynamics model that includes major regulatory pathways, such as the RANK/RANKL/OPG axis, Wnt signaling, and hormonal regulation by estrogen, parathyroid hormone, and TGF-{beta}. We calibrate the model on clinical data from healthy postmenopausal women, and women with reduced BMD undergoing anti-osteoporotic therapy. The calibrated model captures healthy BMD decline in postmenopausal women and therapeutic response to anti-osteoporotic medications. We mechanistically incorporate the effect of 22 variants across 8 genes involved in bone remodeling and simulate BMD trajectories in 1,000 virtual subjects differing by ancestry and genetic makeup. The median predicted 5-year BMD loss was 3.57% (95% prediction interval: 1.31-5.24), consistent with the values reported in the literature. The virtual individuals with African ancestry were predicted to experience the highest average 5-year BMD loss. The strongest genetic risk factors for bone loss were predicted to be CYP19A1 rs727479 and OPG rs3102735, while LRP5 rs11228240 emerged as a protective factor that could partially counteract the detrimental effects of other variants. Several epistatic effects were observed in the genetic interaction analysis. Mechanistically, our model suggested that estrogen exerts its effect on bone remodeling primarily by modulating osteoclast apoptosis. Overall, this framework demonstrates a proof-of-concept for integration of genetic risk factors into mechanistic models of disease and can be extended to other conditions with polygenic inheritance.