Fibroblast growth factor 23 (FGF23) is a bone-derived hormone and growth factor that plays a central role in phosphate and mineral homeostasis. Beyond its classical endocrine actions on the kidney, accumulating evidence indicates that FGF23 exerts broad paracrine and systemic effects that extend to metabolism, inflammation, cardiovascular function and cancer biology. FGF23 production is tightly regulated at the transcriptional and post-translational levels in osteocytes and osteoblasts, resulting in the release of either intact bioactive FGF23 or cleaved fragments with distinct biological properties. Canonical FGF23 signalling requires fibroblast growth factor receptors in complex with the co-receptor α-Klotho, although α-Klotho-independent pathways have been described in several tissues. This review provides a comprehensive overview of FGF23 biology, focusing on its regulation, processing and signalling mechanisms, and integrating current knowledge of its paracrine and endocrine actions across multiple organ systems. We discuss the role of FGF23 in bone mineralisation, phosphocalcium metabolism and energy homeostasis, as well as its involvement in inflammatory states, anaemia, cardiovascular disease, chronic kidney disease, cancer and nervous system function. Experimental and clinical evidence supporting both adaptive and maladaptive roles of FGF23 in health and disease is critically examined. Overall, FGF23 emerges as a multifunctional growth factor and hormone that links bone to systemic metabolic and inflammatory networks. Understanding the context-dependent actions of FGF23 may provide novel insights into disease mechanisms and identify new opportunities for therapeutic intervention.

Inter-organ cross-talk is increasingly recognised as a fundamental determinant in the pathogenesis of neurodegenerative and neuromuscular disorders, modulating neuroinflammation, protein misfolding, and cellular dysfunction through systemic mediators such as cytokines, adipokines, and growth factors. In neuromuscular diseases, particularly Pompe disease, muscle degeneration is tightly linked to impaired autophagy and chronic inflammation. Recent evidence highlights the gut microbiota as a key regulator of innate and adaptive immune responses, exerting direct effects on skeletal muscle and supporting the existence of a gut–muscle axis. Dysbiosis has been proposed to influence myopathy progression, suggesting that modulation of the intestinal ecosystem may hold therapeutic relevance. Consequently, interventions employing probiotics, prebiotics, and targeted nutritional compounds have emerged as promising strategies to modulate immune activity, attenuate inflammation, and enhance autophagic efficiency, thereby contributing to the restoration of intestinal eubiosis and complementing enzyme replacement therapy. In parallel, epigenetic mechanisms are gaining prominence as additional modulators of pathogenic pathways, with the potential to influence microbiome composition and function. Collectively, these insights position the gut–muscle axis as a central regulatory node in Pompe disease and a compelling target for personalised nutritional and nutraceutical approaches. This review aims to provide a comprehensive examination of the gut–muscle axis and its implications in Pompe disease. Understanding how nutrient-induced changes in microbial gene expression may be harnessed to develop novel, synergistic therapeutic strategies could ultimately improve clinical outcomes and enhance the quality of life of affected individuals.

Hypoparathyroidism is a rare endocrine disorder characterized by hypocalcemia, hyperphosphatemia, and low or undetectable levels of parathyroid hormone (PTH). Advanced treatments that precisely maintain blood calcium levels within the normal range to improve disease symptoms and outcomes are needed. Canvuparatide (formerly known as MBX 2109) is a once-weekly investigational PTH analog that undergoes a controlled-release conversion to a biologically active peptide through an intramolecular cyclization reaction controlled by temperature and pH. Here we demonstrate the biologically active PTH analog, derived from the canvuparatide prodrug, stimulated dose-dependent accumulation of cyclic AMP to a similar degree and selectivity as a synthetic form of the human PTH(1–34) peptide in human cells overexpressing the PTH type 1 receptor. In healthy rats treated with canvuparatide at 4–40 nmol/kg/day for 28 days and healthy cynomolgus monkeys treated with single doses of canvuparatide 3.75–7.5 nmol/kg, prodrug and active peptide concentrations increased dose proportionally and correlated with increases in serum calcium concentrations. In parathyroidectomized rats, canvuparatide treatment at 10–40 nmol/kg normalized serum calcium levels and increased bone formation in a dose-proportional manner. In a phase 1, randomized, placebo-controlled study (NCT05158335), single subcutaneously administered doses of canvuparatide (50–600 μg) were well tolerated in healthy volunteers. Pharmacokinetic clinical profiles displayed geometric mean t_1/2 values of 81–101 (canvuparatide prodrug) and 133–186 h (canvuparatide active peptide) across dose groups, supporting once-weekly dosing. These collective findings support clinical advancement of once-weekly canvuparatide therapy for patients with hypoparathyroidism.

Glucagon-like peptide-1 receptor (GLP-1R) activation in the brain strongly reduces appetite, but most brain GLP-1Rs are not accessible for systemically administered GLP-1R agonists. Acute activation of nucleus tractus solitarius (NTS) GLP-1 neurons, known as preproglucagon (PPG) neurons, strongly suppresses food intake separate from GLP-1R agonists. However, it is unknown if chronic stimulation of PPG neurons is a viable strategy for appetite suppression, or if obesity disrupts their function. Here we demonstrate that PPG neurons in the NTS and intermediate reticular nucleus (IRT) determine meal size, and that their total number is inversely correlated with bodyweight gain. We report that PPG^NTS and PPG^IRT neurons receive distinct monosynaptic inputs, but have convergent efferent projection targets throughout the brain, and that combined ablation of both populations delays the onset of physiological satiation to a degree sufficient to promote weight gain under ad libitum chow fed conditions. Crucially, chronic daily chemogenetic activation of PPG^NTS+IRT neurons drives robust and sustained hypophagia and weight loss in obese mice without notable adverse effects, demonstrating their value as targets for obesity pharmacotherapy.

Rod and cone photoreceptors are among the most energy-demanding cells in the body, exhibiting a high rate of ATP consumption. Their primary energy source is glucose, which is metabolized through both glycolysis and mitochondrial pyruvate oxidative phosphorylation. The pyruvate dehydrogenase E1 subunit α1 is a critical component of the pyruvate dehydrogenase, which catalyzes the conversion of pyruvate to acetyl-CoA, thereby regulating mitochondrial pyruvate metabolism. To determine the significance of mitochondrial pyruvate metabolism in these cells, we investigated the impact of photoreceptor-specific Pdha1 deletion in the mouse retina. Rod- or cone-specific Pdha1 knockout mice at 2–5 months were used. These mice were evaluated across multiple modalities, including retinal structure and integrity (morphometry), retinal function (electroretinogram), photoreceptor ultrastructure (transmission electron microscopy), retinal metabolic profiles (mass spectrometry), gene expression (RT-PCR), and retinal stress response (glial activation analysis). Mice with rod- or cone-specific Pdha1 deletion exhibited retinal degeneration phenotype, manifested by impaired retinal morphology and light responses and significant retinal glial activation. Mechanistically, these retinas displayed profound metabolism reprogramming, evidenced by changes in key glycolysis and decreased tricarboxylic acid (TCA) cycle intermediates, carbohydrates, amino acids, nucleotides and their derivatives. This metabolic remodeling was further supported by enhanced glycolysis and decreased TCA cycle gene expression and was accompanied by impaired mitochondrial morphology. Our findings demonstrate that PDHA1 is essential for photoreceptor energy metabolism and for maintaining both their structural and functional integrity, thus highlighting the critical importance of proper mitochondrial glucose metabolism for photoreceptor health.

The existence of an inherent rewiring of metabolic regulation has been demonstrated through studies of obese mice that are fed a normal diet and produce offspring with metabolic disorders. tRNA-derived fragments (tRFs) have been suggested as a potential mediator of this inheritance. To explore a mechanism underlying metabolic stress-induced tRNA fragmentation, we examined the effects of a HFD on tRFs in sperm. Small RNA sequencing on sperm revealed that HFD-induced metabolic changes affect the tRF profiles, showing a trend of decreased 5′-derived tRFs and increased 3′-derived tRFs, suggesting a shift in tRNA cleavage patterns under HFD feeding. In conjunction with the alteration of tRFs, the expression of Ang, which encodes the ribonuclease angiogenin, was significantly increased in the testis. Transcriptome and metabolome analyses indicated that AMPK-mTOR signaling pathway was the possible mediator of these effects, with decreased AMPK activity and increased mTOR activity confirmed at the protein level in the testis. Moreover, in vitro experiments showed that AMPK inhibition led to increased angiogenin expression level and alterations in tRF profile. In vitro angiogenin induction experiments, designed to mimic HFD conditions, produced changes in tRF profiles similar to those observed in HFD-fed mice, although the resulting tRF profiles did not completely recapitulate the in vivo HFD-induced profiles. Our findings suggest that HFD-induced metabolic stress inhibits AMPK during spermatogenesis, leading to increased Ang expression and altered tRF remodeling.

Objectives

Brown adipose tissue (BAT) dissipates energy via non-shivering thermogenesis, but durable thermogenic benefit requires sustained cold remodeling that stabilizes a cold-adapted tissue state. While most studies have focused on adipocyte-intrinsic pathways that drive acute activation, how stromal niche cells—particularly the vasculature—sense and coordinate long-term adaptation remains poorly defined. Because GPCRs are key sensors of extracellular and neurohumoral cues, we mapped GPCR expression across mouse and human BAT at single-nucleus resolution and identified adhesion GPCRs as a prominent family enriched in vascular cells, with endothelial ADGRF5(GPR116) emerging as a leading candidate regulator.

Methods

Single-nucleus RNA sequencing of mouse and human BAT was used to map GPCR expression across cell types. Global, inducible endothelial-specific, and adipocyte-specific ADGRF5(GPR116) knockout mouse models were each challenged with acute and prolonged cold exposure. Endothelial and adipocyte states were analyzed using single-nucleus RNA sequencing transcriptional profiling, functional vascular assays, and cell–cell communication modeling.

Results

Endothelial deletion of ADGRF5(GPR116) impaired the ability of mice to sustain thermogenesis during prolonged cold exposure, whereas adipocyte-specific deletion did not affect thermogenic capacity in vivo. Loss of endothelial ADGRF5(GPR116) did not alter endothelial cell abundance, but induced endothelial transcriptional reprogramming characterized by disrupted quiescent remodeling programs, shifts in endothelial state with EndMT-like features, and context-dependent alterations in barrier-associated pathways, occurring in the absence of immune cell infiltration or overt fibrosis. Adipocyte reclustering revealed a failure to acquire a fully cold-adapted thermogenic state, with thermogenically inefficient programs and adrenergic hyporesponsiveness, despite preserved sympathetic input. CellChat and NicheNet analyses predicted altered endothelial-derived paracrine signaling capable of reshaping adipocyte identity.

Conclusions

Endothelial ADGRF5(GPR116) is a critical regulator of vascular adaptation during sustained cold exposure and supports full acquisition of the thermogenic adipocyte state through endothelial identity and paracrine signaling.

Graphical abstract

During prolonged cold exposure, endothelial ADGRF5(GPR116) is required to maintain a homeostatic angiocrine environment that stabilizes thermogenic adipocyte identity and sustains energy expenditure. In wild-type brown adipose tissue, ADGRF5(GPR116)-expressing endothelial cells support adaptive intercellular communication and long-term thermogenic competence. Loss of endothelial ADGRF5(GPR116) during cold adaptation leads to altered endothelial signaling and maladaptive intercellular communication within the adipose microenvironment, resulting in impaired maintenance of thermogenesis despite preserved tissue structure.

The liver plays a pivotal role in glucose homeostasis, adapting to metabolic challenges through transcriptional and post-transcriptional mechanisms. While the RNA-binding protein HuR/ELAVL1 is known to regulate mRNA stability during development and stress, its role in adult liver energy metabolism remains largely unexplored. Here, we demonstrate that hepatic HuR expression is dynamically induced in response to diverse metabolic challenges, including in vivo models of fasting (glucagon stimulation), caloric restriction, high-fat diet (HFD), and type 2 diabetes (T2D). Mechanistically, HuR modulates Cebpb mRNA, thereby enhancing the expression of phosphoenolpyruvate carboxykinase (PCK1), a key gluconeogenic enzyme.

This interaction was assessed by in vivo immunoprecipitation and sequencing of ribonucleoprotein (RNP) complexes from mouse liver, which confirmed Cebpb modulation HuR-dependent.

Silencing hepatic Elavl1 via siRNA delivery downregulated the C/EBPβ/PCK1 axis, increased glycogen synthesis, and improved hepatic insulin sensitivity and glycemic control. Furthermore, this increase in hepatic glycogen content led to reduced food intake, adiposity, and body weight in both healthy and diabetic mice. Collectively, our in vivo findings uncover HuR as a central post-transcriptional regulator of glucose metabolism in the liver and position it as a promising therapeutic target in metabolic disease.

Objectives

Skeletal muscle is a central regulator of metabolic health, serving as the primary site of postprandial glucose uptake and playing a critical role in whole-body insulin sensitivity. Despite its importance, the molecular mechanisms governing muscle differentiation (myogenesis) and their modulation by metabolic interventions remain poorly defined. This study identifies the clathrin adaptor protein Picalm (phosphatidylinositol-binding clathrin assembly protein) as a novel regulator of myogenesis and investigates its regulation in response to exercise training and intermittent fasting.

Methods

Functional characterization of Picalm was conducted in C2C12 myoblasts and primary myocytes using siRNA-mediated knockdown. Clathrin-mediated endocytosis was performed using dynamin inhibition (Dyngo-4a) and via an EGF internalization assay. Surface proteome alterations were analyzed by plasma membrane proteomics, and autophagy dynamics were assessed via immunoblotting and fluorescence imaging. Jasplakinolide was used to rescue differentiation defects by enhancing actin polymerization.

Results

Picalm-depleted C2C12 myoblasts exhibited impaired differentiation, presumably due to diminished intracellular trafficking dynamics of cell surface proteins. Inhibition of dynamin-dependent endocytosis phenocopied the differentiation defect and further aggravated myogenesis in Picalm-depleted cells, indicating that Picalm-dependent endocytic function is required for efficient differentiation. Consistent with this, Picalm knockdown significantly decreased clathrin-dependent uptake of EGF. Proteome analysis of a plasma membrane-enriched fraction revealed increased abundance of over 100 proteins after Picalm knockdown, particularly candidates involved in vesicular trafficking (Vamp3, Vamp5), actin remodeling (Actn1, Actn4, Rhog, Rock1, Rock2) and cell adhesion (integrin receptors). In line with this, Picalm knockdown resulted in impaired maturation and lysosomal degradation of autophagic vesicles. Remarkably, pharmacological stabilization of actin filaments with Jasplakinolide restored myogenic differentiation in Picalm-deficient cells, highlighting a functional link between actin remodeling and myogenesis.

Conclusions

Picalm regulates skeletal muscle differentiation by supporting clathrin-mediated endocytosis and plasma membrane remodeling, thereby maintaining trafficking-dependent control of actin organization. Its expression is responsive to metabolic cues such as exercise and intermittent fasting. These findings reveal a novel molecular link between nutrient signaling and myogenesis, with implications for metabolic disease and muscle regeneration.

Leptin receptor (LepRb)-expressing neurons integrate metabolic and reproductive signals, yet the role of insulin-like growth factor 1 receptor (IGF1R) signaling within these neurons remains unclear. Because IGF-1 and insulin can partially activate each other’s receptors, we generated mice lacking IGF1R selectively in LepRb neurons (IGF1R^LepRb) as well as mice lacking both IGF1R and insulin receptor (IR) in LepRb neurons (IGF1R/IR^LepRb). These models were used to assess body growth, skeletal development, reproductive function, energy balance, and metabolic homeostasis. Deletion of IGF1R alone in LepRb neurons delayed pubertal onset, impaired adult fertility, and accelerated reproductive aging, accompanied by transient postnatal growth retardation. IGF1R deficiency also altered trabecular and cortical bone structural parameters in both sexes, supporting a role for IGF1R signaling in coordinating growth, skeletal physiology, and reproductive function. Despite reduced food intake and increased energy expenditure in females after adjusting for lean mass, IGF1R deletion caused only modest metabolic alterations, with transient decreases in body weight and largely unchanged body composition and locomotor activity. In contrast, combined deletion of IGF1R and IR in LepRb neurons resulted in marked metabolic disturbances, including increased adiposity, reduced lean mass, lower energy expenditure, decreased locomotor activity, and impaired insulin sensitivity in males. These findings indicate cooperative roles of IGF1R and IR signaling within LepRb neurons in regulating body composition, energy balance, and glucose homeostasis. Together, our results demonstrate that IGF1R signaling in LepRb neurons primarily regulates reproductive development, skeletal physiology, and growth, whereas combined IGF1R and IR signaling is required for maintaining metabolic homeostasis. These findings identify LepRb neurons as an important neuroendocrine hub integrating IGF and insulin signaling to coordinate growth, reproduction, and metabolism in a sex-dependent manner.

During pregnancy, the heart undergoes major physiological and metabolic changes to increase cardiac workload, and the demand for energy production is especially elevated during the trial of labor. Normally, cardiac structure and metabolism revert to the pre-pregnancy state shortly after delivery. However, in some cases, peripartum/postpartum cardiomyopathy (PPCM) occurs, which increases a person's risk of major cardiac events following pregnancy. The molecular mechanisms underlying PPCM remain poorly understood. In this study, we investigate the transcriptional, metabolic, and bioenergetic profiles of postpartum (PP) hearts in a mouse model of cardiomyopathy caused by the pathogenic p.S55L mutation in the mitochondrial protein coiled-coil-helix-coiled-coil-helix domain containing 10 (CHCHD10). Heterozygote p.S55L mutant CHCHD10 mice develop acute heart failure during the immediate PP period. We observe cardiac remodeling, mitochondrial stress, and profound metabolic rewiring in PP mutant CHCHD10 hearts. Metabolic rewiring results in decreased levels of heme and the depletion of key cofactors of energy metabolism, including NAD(H) and ADP. These findings suggest that mutant CHCHD10 hearts fail to meet the increased energy demands associated with the trial of labor due to the insufficient turnover rate of NAD+/NADH and ADP/ATP. We propose that this metabolic insufficiency drives PP mortality in mutant CHCHD10 mice. In support of this hypothesis, dietary supplementation with nicotinamide riboside and pterostilbene, a naturally derived polyphenol, increased PP survival and cardiac energy metabolites in mutant CHCHD10 mice. Our work provides novel insights into the molecular mechanisms of PP cardiomyopathy associated with mitochondrial stress and suggests potential benefits of dietary NAD(H) supplementation.

Energy metabolism plays a crucial role in determining the aggressiveness of cancer. In this study, we assessed the impact of drug-induced modulation on the expression and prognostic significance of crucial factors involved in glycolytic metabolism: lactate dehydrogenase A (LDH-A) and glucose transporter type 1 (GLUT-1). In patient samples diagnosed with pleural Malignant Mesothelioma (MM), expression levels of LDH-A and GLUT-1 were studied both at baseline and after platinum-based-chemotherapy. High GLUT-1 and LDH-A levels were associated with shorter survival, and chemotherapy increased GLUT-1 expression, further correlating with poor prognosis. Utilizing LDH-A (NHI-2) and GLUT-1 (PGL14) inhibitors, we examined their effects on migration and apoptosis in immortalized (H2052, H2452) and primary (STO, MESO-II) MM cells. PGL14 and NHI-2 decreased migration, increased reactive oxygen species (ROS) and apoptosis rates. Inhibitors, both single and in combination, disintegrated the MM spheroids, while the bioluminescence from spheroid-forming cells decreased from 1.3 × 10⁵ in the control group to 9.7 × 10⁴ and 7.1 × 10⁴ [RLU/s] after NHI-2 and PGL14/NHI-2 treatment, respectively. Overexpression and chemotherapy-induced modulation of LDH-A and GLUT-1 correlated with poor MM prognosis. Combined inhibition of these two metabolic determinants impeded MM cell migration, stimulated ROS production and apoptosis, and affected spheroids’ growth, offering promise for new treatment development.

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are mainstay therapies for diabetes and obesity, acting in part by enhancing glucose-dependent insulin secretion. While the primary cilium is a known signaling compartment for certain G-protein coupled receptors (GPCRs), its role in the β-cell response to incretins remains undefined. Here, we show that primary cilia are essential for full GLP-1R signaling. Loss of β-cell cilia in mouse and human islets severely impaired GLP-1-potentiated insulin secretion, an effect preceded by blunted whole-cell cAMP and Ca²⁺ responses. Immunofluorescence and immunogold scanning electron microscopy revealed endogenous GLP-1R localized to the primary cilium. Adenylyl cyclase immunostaining was also enriched within cilia, and targeted inhibition of ciliary PKA reduced insulin secretion. Critically, disrupting ciliary GPCR trafficking via Tulp3 knockdown – while preserving cilia structure – recapitulated the signaling and secretory deficits, demonstrating a specific requirement for the ciliary receptor pool. These findings establish the primary cilium as a non-redundant signaling compartment for GLP-1R and uncover a new layer of subcellular organization in incretin action in β cells.

Background

Metabolic dysfunction is a defining feature of amyotrophic lateral sclerosis (ALS), emerging early and strongly associated with disease progression and prognosis. While systemic hypermetabolism is well documented, the central mechanisms underlying energy imbalance remain poorly understood. The hypothalamus, a key regulator of whole-body energy homeostasis, has recently been implicated in ALS, but its mechanistic contribution to metabolic failure and disease progression remains unclear.

Methods

We analyzed the hypothalamus SOD1-G93A mouse model using proteomics (ProteomeXchange ID: PXD070931), mitochondrial bioenergetic assays, immunofluorescence, flow cytometry, and gene expression to assess hypothalamic mitochondrial function, glial activation, and melanocortin system integrity. Limited analyses in the hFUS model confirmed the presence of key hypothalamic alterations, supporting a shared vulnerability across ALS models. In SOD1-G93A mice, the metabolic modulator trimetazidine (TMZ) was administered presymptomatically to evaluate effects on hypothalamic pathology, metabolic regulation, disease onset, and survival.

Findings

We provide the first evidence that mitochondrial bioenergetic defects arise specifically in the hypothalamus of ALS models before symptom onset. Proteomic profiling revealed dysregulation of mitochondrial pathways, while functional assays confirmed impaired bioenergetics in the hypothalamus. These deficits were accompanied by local pro-inflammatory activation of astrocytes and microglia, mitochondrial dysfunction in glial cells, and early disruption of the arcuate nucleus melanocortin system. Limited analyses in hFUS mice confirmed selective hypothalamic vulnerability.

Early TMZ treatment in SOD1-G93A mice specifically restored hypothalamic bioenergetics, normalized local glial activation and melanocortin signaling, delayed disease onset, and extended survival.

Interpretation

These findings establish the hypothalamus as an early and selectively vulnerable site in ALS, where region-specific mitochondrial dysfunction contributes to metabolic and neuroinflammatory alterations. Targeting hypothalamic bioenergetics represents a promising therapeutic strategy.

Bile acids (BAs) play an important role in systemic metabolic improvements following bariatric surgery. In this study, we found that orally administered norursodeoxycholic acid (norUDCA), a conjugation-resistant C23 derivative of naturally occurring UDCA, accumulated in peripheral organs including heart and brown adipose tissue (BAT). Moreover, norUDCA decreased systemic levels of endogenous conjugated BAs, while increasing unconjugated BAs. Notably, in addition to beneficial effects in a cholestatic liver disease model, norUDCA also lowered plasma glucose and fat mass in mice, suggesting that this BA derivative could be repurposed for treating obesity-associated cardiometabolic diseases. Metabolic energy expenditure studies, however, revealed that norUDCA-treated mice have impaired BAT capacity and developed intolerance to cold stress, a phenotype exacerbated in mice lacking adipose ATGL-dependent lipolysis. Transcriptomic and metabolic analyses demonstrated tissue remodeling in heart and BAT that involved pronounced changes in energy substrate utilization, including enhanced cardiac glucose uptake and higher ketone body utilization in BAT. Importantly, co-administration of a low-carb diet prevented cold stress-induced metabolic deficits. Mechanistic studies in human engineered heart tissue indicated that norUDCA compromised contractile function. In conclusion, these data suggest that conjugation-resistant BA derivatives like norUDCA impair myocardial and BAT energetics by altering glucose, lipid, and energy metabolism, particularly during catabolic cold stress conditions.

Cellular identity is fundamentally determined by the precise regulation of protein synthesis, which governs growth, differentiation, and function. In the pancreas, the balance between exocrine and endocrine cell types is critical for organ function, and the disruption of protein synthesis in these cells can lead to diseases such as exocrine insufficiency and diabetes. The specialized mRNA translation factor eukaryotic initiation factor 5A (eIF5A) has emerged as an essential regulator of on-demand protein synthesis in professional secretory cells. Here, we investigate the role of eIF5A-mediated mRNA translation in lineage specification during pancreas development. Using genetic mouse models, our studies reveal that loss of eIF5A results in a marked reduction of exocrine volume and a paradoxical expansion of the insulin-producing beta cell population. We reveal that these cellular changes are driven by impaired on-demand protein synthesis during the critical stage of pancreatic cell differentiation. Mechanistically, we show that eIF5A deficiency disrupts the synthesis of proteins critical for proper pathway signaling—most notably Notch—that instruct cell fate decisions. As a result, we observe impaired ductal branching and tip formation as well increased Ngn3+ endocrine progenitors within the ducts. These changes in lineage allocations directly contribute to decreased acinar cell and increased beta cell mass. Remarkably, eIF5A-deficient mice maintain elevated beta cell mass and exhibit preserved glucose tolerance despite severe exocrine deficiency. Collectively, our findings establish that eIF5A-mediated mRNA translation regulates critical developmental signaling pathways and reinforces the finding that disruptions in protein synthesis can reprogram cellular identity and drive disease pathogenesis.

Endothelial cells (ECs) are central regulators of vascular and metabolic homeostasis, yet their organ- and depot-specific diversity remains underexplored. Two major types of adipose tissue (AT) can be distinguished that differ substantially in their physiological function and vascularization: white AT (WAT), which is the major energy storage and brown AT (BAT), which is highly vascularized and dissipates energy [1–5]. While ECs from these depots likely contribute to adipose function, their characterization has been hindered by technical limitations in isolation and culture. Here, we establish a protocol for isolating and expanding ECs from murine BAT and WAT, enabling transcriptomic and functional analyses across depots. We demonstrate that freshly isolated BAT-ECs express depot-enriched gene signatures, including Rgcc, Cdkn1c, Tcf15, Meox2, and Efnb1, several of which are dynamically regulated during cold-induced BAT activation. These findings reveal novel BAT-EC markers and highlight specialized endothelial programs that may support BAT function. However, we also uncover that culturing BAT-ECs profoundly remodels EC identity. Transcriptomic profiling shows that BAT-ECs rapidly downregulate BAT-enriched endothelial markers and acquire features resembling WAT-ECs. This dedifferentiation is accompanied by signatures of proliferation, adhesion remodeling, and endothelial-to-mesenchymal transition. While these changes present challenges for maintaining depot-specific identity in culture, they also provide a framework to better interpret experimental outcomes and to investigate EC plasticity. Taken together, our study delivers a novel isolation and culture protocol for adipose ECs, defines BAT-EC markers, and demonstrates how culture conditions reshape their identity. These insights build the foundation for future research of AT vasculature.

Adiponectin (Adpn) is a potent insulin-sensitizing adipokine with therapeutic promise for type 2 diabetes (T2D) and metabolic dysfunction-associated steatohepatitis (MASH). Its clinical use is limited by challenges in producing stable, bioactive high-molecular weight forms. Adipocyte-derived extracellular vesicles (EVs) naturally carry oligomeric Adpn on their surface, enhancing hormone stability and activity. Here, we engineered EVs displaying membrane-anchored Adpn (EV^PP−Adpn) and control EVs lacking Adpn (EV^CTL), and evaluated their metabolic effects in high fat diet (HFD)-induced obesity mice.

EV^PP−Adpn were purified from HEK293T cells stably transfected with a chimeric Adpn fused to a transmembrane domain and a pilot peptide (PP) directing it to EVs; EV^CTL were produced from non-transfected cells. HFD-fed male and female mice received intraperitoneal EV injections for six weeks.

EV^PP−Adpn improved glucose tolerance and insulin sensitivity, promoted adipocyte lipid storage through insulin-regulated lipogenesis and alleviated MASH features (liver steatosis, inflammation and fibrosis). EV^PP−Adpn lowered circulating ceramides and reduced FGF21, indicating improved hepatic metabolism, and activated AKT and AMPK pathways in liver and skeletal muscle, consistent with increased adiponectin signaling.

These results demonstrate that surface-anchored Adpn EVs restore tissue-specific insulin signaling and improve obesity-related metabolic dysfunctions, highlighting their potential as a novel biotherapeutic strategy for T2D and MASH.