Biology subjects

Deshmukh, A. S.

Publications and source records attributed to Deshmukh, A. S..

18 recordsLinked to original sources

bioRxiv2026

Integrated Single-Fiber Multi-Omics Links an Inflammatory-Associated Myofiber State to Altered Myosin Dynamics in Patients with ICU-acquired weakness

Skeletal muscle dysfunction is a pervasive complication of critical illness that worsens survival and recovery, yet remains poorly explained by current clinical or molecular markers. To directly connect disease-associated molecular states to the contractile machinery, this study combined sequential functional, transcriptomic, and proteomic profiling of the same single human skeletal myofibers from critically ill patients in the intensive care unit with acquired weakness (ICU-AW) and controls. Despite marked donor-level heterogeneity, integrated analysis revealed a subtle yet conserved myofiber state enriched in ICU-AW, characterized by inflammatory and chemotactic gene programs, intracellular structural remodeling, and bioenergetic adaptation. Nineteen features were significantly altered at both RNA and protein levels from the same myofiber, linking an inflammatory transcriptional landscape to a proteomic shift toward mitochondrial and translational machinery and away from membrane-associated signaling. Functionally, fibers in this state displayed selectively disrupted myosin dynamics, evidenced by prolonged ATP turnover time of myosin heads in their super-relaxed conformation, implicating altered myosin energetics as a contributor to muscle dysfunction. These findings define a discrete, disease-associated myofiber state and establish an integrative single-fiber framework for connecting multi-omic heterogeneity to molecular motor function in complex human disease. Graphical AbstractSingle-fiber multi-omic and functional analysis reveals a stress-adapted myofiber state in ICU-AW. Specifically, for the present study, myofibers from ICU-AW donors and control donors were isolated and functionally profiled for myosin dynamics before being split for simultaneous transcriptomic and proteomic analysis. Integrated analysis then identified a reproducible fiber phenotype enriched in ICU-AW, characterized by inflammatory transcriptional signatures coordinated with mitochondrial proteomic remodeling and altered myosin super-relaxed state energetics. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=95 SRC="FIGDIR/small/706099v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@95715forg.highwire.dtl.DTLVardef@1462ff8org.highwire.dtl.DTLVardef@f74996org.highwire.dtl.DTLVardef@10055ec_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2025

Deconvoluting fiber type proportions from human skeletal muscle transcriptomics and proteomics data using FibeRtypeR

Muscle fibers are the dominant, multinucleated cell type in skeletal muscle. In humans, they can be classified as slow (type 1) and fast (type 2) fibers, traditionally based on distinct properties of their contractile machinery. Slow and fast fibers are characterized by shared and specific cellular complexities that are pivotal for their adaptive capacity to exercise or role in metabolic disease progression. In this era of omics research, there is a critical need to accurately infer muscle fiber type proportions from bulk tissue omics datasets, as single-fiber approaches are not feasible in large-scale or retrospective studies. Here we present FibeRtypeR, an easy-to-use web application to accurately estimate fiber type proportions from bulk transcriptomics and proteomics datasets: https://muscleapps.ugent.be. FibeRtypeR exploits transcriptomics and proteomics profiles of 1000 fiber-typed individual human skeletal muscle fibers as a reference dataset and is validated against paired immunohistochemical fiber type determinations in 160 muscle biopsies. We show that FibeRtypeR can be applied to public datasets, illustrating the application potential across a wide range of biological contexts such as aging, disease and exercise training. This new freely accessible computational tool will prove valuable to the skeletal muscle research community. Key pointsO_LIBulk muscle omics datasets lack fiber type specific information C_LIO_LIOur new tool, FibeRtypeR, leverages in-house collected single-fiber profiles allowing for accurate fiber type inference C_LIO_LIFibeRtypeR is methodologically robust across omics technologies and workflows C_LIO_LIWe host FibeRtypeR as an intuitive open-access Shiny app, applicable to new and publicly available transcriptomics and proteomics datasets C_LI

physiology↗

bioRxiv2025

The metabolic and molecular mechanisms underlying running-induced energy compensation

Exercise not only regulates energy expenditure but also appetite, yet the underpinnings remain unclear. We describe that increased energy intake is a defense against energy loss that depends on initial running distance and operates independently of diet and age. Running caused a rapid circadian-dependent fat remodeling leading to a decline in circulating leptin accompanied by the activation of hypothalamic neurons. We discovered that the activation of the {beta}3-adrenergic receptor drives running-induced fat loss and the lower leptin triggers energy compensation by upregulating Neuropeptide Y. Once energy compensation is achieved, running is associated with molecular changes in hypothalamic signaling related to appetite and functional adaptations, such as enhanced sensitivity to hunger and satiety signals and increased responsiveness to appetite suppression induced by -Melanocyte-Stimulating Hormone. The increased food intake persisted without fat rebound beyond running in both lean and obese young mice, uncovering a new homeostatic balance in young mice.

physiology↗

bioRxiv2025

Body Fluid Proteomic Landscape of Acute Exercise

Physical activity improves health, yet the molecular mechanisms remain partially understood. This study presents a high-resolution, time-resolved atlas profiling 10,127 proteins across plasma, saliva, and urine from healthy adults post-acute exercise. Exercise regulated over 3,000 proteins, revealing distinct, fluid-specific temporal dynamics. By integrating fluid-specific exercise signatures with tissue and disease atlases, we delineated the contribution of tissues and associations to various diseases. Network analysis across body fluids elucidated coordinated remodeling in the extracellular matrix and immune activation orchestrating exercise-induced networks. Many exercise-responsive plasma proteins were robust across age, sex, and exercise modalities, indicating a conserved systemic signature. Integration with genetic data established exercise-regulated proteins as modulators of metabolic traits and identified over 200 targeted by approved drugs, highlighting their impact on disease-relevant pathways. This comprehensive atlas, available as an open-access resource https://cbmr.ku.dk/research/research-groups/deshmukh-group/shiny-apps/, advances our molecular insight into exercise adaptations and enables exerkine discovery, biomarker development, and pharmacological exercise-mimetic strategies. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/656705v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@bf3baforg.highwire.dtl.DTLVardef@e79b11org.highwire.dtl.DTLVardef@1757b9borg.highwire.dtl.DTLVardef@5fddc_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIExercise induces robust and distinct changes across body fluid proteomes C_LIO_LITissue remodeling and immune activation drive exercise-induced network expansion C_LIO_LI[~]1,000 exercise-regulated plasma proteins are age, exercise mode, or sex-specific C_LIO_LIGenetic inference identifies druggable exerkines that regulate health and disease C_LI

physiology↗

bioRxiv2025

Muscle Cathepsin B treatment improves behavioral and neurogenic deficits in a mouse model of Alzheimer's Disease

Muscle secretes factors during exercise that enhance cognition. Myokine Cathepsin B (Ctsb) is linked to memory function, but its role in neurodegenerative disease is unclear. Here we show that AAV-vector-mediated Ctsb overexpression in skeletal muscle in an Alzheimers Disease (AD) mouse model (APP/PS1), improves motor coordination, memory function and adult hippocampal neurogenesis, while plaque pathology and neuroinflammation remain unchanged. Additionally, in AD mice, Ctsb treatment modifies hippocampal, muscle and plasma proteomic profiles to resemble that of wildtype controls. Conversely, in wildtype mice, Ctsb expression causes memory deficits and results in protein profiles across tissues that are comparable to AD control mice. In AD mice, Ctsb treatment increases the abundance of hippocampal proteins involved in mRNA metabolism and protein synthesis, including those relevant to adult hippocampal neurogenesis and memory function. Furthermore, Ctsb treatment enhances plasma metabolic and mitochondrial processes, and reduces inflammatory responses. In muscle, Ctsb expression elevates protein translation in AD mice, whereas in wildtype mice mitochondrial proteins decrease. Overall, the biological changes in the treatment groups are consistent with effects on memory function. Thus, skeletal muscle Ctsb application has potential as an AD therapeutic intervention.

neuroscience↗

bioRxiv2024

The apicomplexan DedA superfamily protein VMP1 is crucial for the biogenesis and function of secretory organelles

Apicomplexan parasites, including Plasmodium falciparum and Toxoplasma gondii, contain specialized secretory organelles such as micronemes, rhoptries, and dense granules, which are essential for parasite motility, host cell invasion, development, and egress. DedA superfamily proteins are implicated in lipid mobilization, which is a key requirement for organelle biogenesis. Herein, we identified and investigated the vacuole membrane protein 1 (VMP1), a DedA superfamily member, of P. falciparum (PfVMP1) and T. gondii (TgVMP1). PfVMP1 and TgVMP1 are ER-localized lipid scramblases. TgVMP1 depletion adversely affected parasite development, motility, host cell invasion, and egress. These phenotypes were consistent with impaired rhoptry and dense granule biogenesis, and decreased secretion of micronemes, rhoptries, and dense granules in TgVMP1-depleted parasites, indicating a crucial role for TgVMP1 in the biogenesis and function of these organelles. TgVMP1 depletion impaired lipid droplet homeostasis and ER organization. Restoration of the ER-localized lipid scramblase by complementing TgVMP1-depleted parasites with PfVMP1 or a homolog as distant as human VMP1 rescued the depleted parasites, indicating their functional conservation and a crucial role for ER-resident lipid scramblase activity in the biogenesis and function of secretory organelles. The essentiality of TgVMP1 for parasite development and likely functional conservation of apicomplexan VMP1 proteins highlight their drug-target potential.

cell biology↗

bioRxiv2024

Integrated single cell functional-proteomic profiling of human skeletal muscle reveals a shift in cellular specificity in nemaline myopathy

Skeletal muscle is a complex syncytial arrangement of an array of cell types and, in the case of muscle specific cells (myofibers), sub-types. There exists extensive heterogeneity in skeletal muscle functional behaviour and molecular landscape, at the cell composition, myofiber sub-type and intra-myofiber sub-type level. This heterogeneity highlights limitations in currently applied methodological approaches, which has stagnated our understanding of fundamental skeletal muscle biology in both healthy and myopathic contexts. Here, we developed a novel approach that combines a fluorescence based assay for the biophysical examination of the sarcomeric protein, myosin, coupled with same-myofiber high sensitivity proteome profiling, termed Single Myofiber Protein Function-Omics (SMPFO). Successfully applying this approach to healthy human skeletal muscle tissue, we identify the integrate relationship between myofiber functionality and the underlying proteomic landscape that guides divergent, but physiologically important, behaviour in myofiber sub-types. By applying SMPFO to two forms of human nemaline myopathy (ACTA1 and TNNT1 mutations), we reveal significant reduction in the divergence of myofiber sub-types, across both biophysical and proteomic behaviour. Collectively, we develop SMPFO as a novel approach to study skeletal muscle with greater specificity, accuracy and resolution then currently applied methods, facilitating that advancement in understanding of SkM tissue in both healthy and diseased states.

physiology↗

bioRxiv2024

Muscle fiber proteomics reveals sex- and fiber type-specific adaptations to resistance training

Skeletal muscle hypertrophy is a hallmark of resistance training that positively impacts health and longevity. However, despite physiological differences between sexes and fiber types, the underlying proteome changes with resistance training have not been studied in a sex- and fiber type-specific manner. Herein, we show sex differences in the fiber type-specific proteome, predominantly in type II fibers. Following 8 weeks of resistance training, substantial remodeling of the human skeletal muscle proteome occurred in a sex- and fiber type-specific manner. Notably, type II fibers exhibited much greater adaptations across both sexes, whereas the main sex-difference was a greater remodeling of intermediate filaments in females. In addition, baseline abundance of proteins involved in translation was highly correlated with fiber hypertrophy, and differed between sexes and fiber types. Thus, translational capacity may partially explain differences in resistance training-induced hypertrophy. Our findings demonstrate key aspects of sex- and fiber type differences in muscle physiology and their contributions to resistance training-induced adaptions.

physiology↗

bioRxiv2024

Molecular Landscape of Modality-Specific Exercise Adaptation in Human Skeletal Muscle through Large-Scale Multi-OMICs Integration

We conducted a large-scale, statistically powered, meta-analysis of exercise adaptations in human skeletal muscles, integrating epigenetic, transcriptomic, transcription factors, and proteomic data across 12 independent cohorts comprising over 1000 participants and 2340 human muscle samples. Our study identified distinctive signatures associated with maximal oxygen consumption (VO2max), and identified five genes robustly intersecting multi-OMIC layers. Notably, transcription factors predominantly functioned as activators across these layers, regulating expression of target genes irrespective of whether DNA methylation levels were low or high, indicating a synergistic effect between TFs and the methylome. Analysis of distinct exercise modalities (aerobic and resistance exercise) revealed unique gene pathways, contrasting with patterns observed in inactivity (muscle disuse) studies. These findings offer a comprehensive understanding of exercise and modality-specific adaptations, shedding light on muscle health and the molecular mechanisms associated with cardiorespiratory fitness, aging, and disease prevention.

molecular biology↗

bioRxiv2024

Dysregulated Skeletal Muscle Myosin Super-relaxation in Type II, but Not Type I, Diabetes Mellitus

Disrupted energy balance is critical for the onset and development of Type II diabetes. The exact underlying metabolic mechanisms remain incomplete but skeletal muscle is thought to play an important pathogenic role. As the super-relaxed state of its most abundant protein, myosin, regulates cellular energetics, here, we aimed to investigate whether it is altered in patients with type II diabetes. For that, we used vastus lateralis biopsy specimens (obtained from patients with type II diabetes and matched controls) and run a combination of structural and functional assays consisting of loaded Mant-ATP chase experiments, X-ray diffraction and LC-MS/MS proteomics in isolated muscle fibres. Our studies revealed a greater muscle myosin super-relaxation and decreased cellular ATP demand in patients than controls. Subsequent proteomic analyses indicated that these (mal)adaptations likely originated from remodeled sarcomeric proteins and greater myosin glycation levels in patients than controls. Overall, our findings emphasize a complex molecular dysregulation of myosin super-relaxed state and energy consumption in type II diabetes. Ultimately, pharmacological targeting of myosin could benefit skeletal muscle and whole-body metabolic health through the enhancement of ATP consumption. Significance StatementMyosin super-relaxation, essential for the regulation of skeletal muscle metabolic rate, is disrupted in type II diabetes due to protein hyper-glycation. As a consequence, myosin ATP demand is significantly lowered. Overall, our findings provide a strong rationale for the use of activators of myosin ATPase to enhance basal energy expenditure in type II diabetes.

cell biology↗

bioRxiv2024

Personalized Molecular Signatures of Insulin Resistance and Type 2 Diabetes

HighlightsO_LIAdvanced proteomics analysis reveals personalized signatures of insulin resistance C_LIO_LIFasting muscle proteome and phosphoproteome predicts whole-body insulin sensitivity C_LIO_LIInsulin-stimulated phosphoproteome reveals selective insulin resistance signatures C_LIO_LIPhosphoproteome and proteome atlas explains sex-specific muscle metabolism C_LI O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=143 SRC="FIGDIR/small/578994v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@a83000org.highwire.dtl.DTLVardef@1e77336org.highwire.dtl.DTLVardef@3d1ecdorg.highwire.dtl.DTLVardef@b1592b_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical AbstractC_FLOATNO C_FIG Insulin resistance is a hallmark of type 2 diabetes, which is a highly heterogeneous disease with diverse pathology. Understanding the molecular signatures of insulin resistance and its association with individual phenotypic traits is crucial for advancing precision medicine in type 2 diabetes. Utilizing cutting-edge proteomics technology, we mapped the proteome and phosphoproteome of skeletal muscle from >120 men and women with normal glucose tolerance or type 2 diabetes, with varying degrees of insulin sensitivity. Leveraging deep in vivo phenotyping, we reveal that fasting proteome and phosphoproteome signatures strongly predict insulin sensitivity. Furthermore, the insulin-stimulated phosphoproteome revealed both dysregulated and preserved signaling nodes - even in individuals with severe insulin resistance. While substantial sex-specific differences in the proteome and phosphoproteome were identified, molecular signatures of insulin resistance remained largely similar between men and women. These findings underscore the need for precision medicine approaches in type 2 diabetes care, acknowledging disease heterogeneity.

biochemistry↗

bioRxiv2023

Insulin and Exercise-induced Phosphoproteomics of Human Skeletal Muscle Identify REPS1 as a New Regulator of Muscle Glucose Uptake

Skeletal muscle regulates glucose uptake in response to insulin and exercise which is critical for maintaining metabolic health. We conducted a comprehensive phosphoproteomic analysis of skeletal muscle from healthy people in response to an acute bout of exercise or insulin stimulation by a hyperinsulinemic euglycemic clamp. Our analysis revealed 233 phosphosites regulated by both exercise and insulin of which most phosphosites were regulated in opposite directions. However, 71 phosphosites on 55 proteins displayed regulation in the same direction, indicating a potential convergence of signaling pathways. We identified the vesicle-associated protein, REPS1, to be phosphorylated at Ser709 in response to both insulin and exercise. REPS1 protein level and Ser709 phosphorylation were closely related to insulin-stimulated glucose uptake in skeletal muscle and required for maximal insulin-stimulated glucose uptake. Furthermore, we observed that insulin triggered phosphorylation of REPS1 Ser709 via P90S6 kinase (RSK) and is impaired in mice and humans with insulin resistance. Collectively, REPS1 is a convergence point for insulin and exercise signaling and a promising therapeutic target in insulin resistance.

biochemistry↗

bioRxiv2023

Beyond Myosin Heavy Chains: Ribosomal Specialization Drives Human Skeletal Muscle Fiber Heterogeneity

Skeletal muscle is an inherently heterogenous tissue comprised primarily of myofibers, which are historically classified into three distinct fiber types in humans: one "slow" (type 1) and two "fast" (type 2A and type 2X), delineated by the expression of myosin heavy chain isoforms (MYHs). However, heterogeneity between and within traditional fiber types remains underexplored. Indeed, whether MYHs are the main classifiers of skeletal muscle fibers has not been examined in an unbiased manner. Through the development and application of novel transcriptomic and proteomic workflows, applied to 1050 and 1038 single muscle fibers from human vastus lateralis, respectively, we show that MYHs are not the only principal drivers of skeletal muscle fiber heterogeneity. Instead, metabolic, ribosomal, and cell junction proteins are a source of multi-dimensional variation between skeletal muscle fibers. Furthermore, whilst slow and fast fiber clusters can be identified, described by their contractile and metabolic profiles, our data suggests that type 2X fibers are not phenotypically distinct to other fast fibers at an omics level. Moreover, MYH-based classifications do not adequately describe the phenotype of skeletal muscle fibers in one of the most common genetic muscle diseases, nemaline myopathy, with fibers shifting towards a non-oxidative phenotype independently of MYH-based fiber type. We also characterize novel transcriptomic and proteomic features of slow and fast skeletal muscle fibers, including identifying several muscle fiber type-specific polypeptides, termed microproteins, encoded by transcripts annotated as non-coding RNA. Overall, our data indicates that skeletal muscle fiber heterogeneity is multi-dimensional with sources of variation beyond myosin heavy chain isoforms.

physiology↗

bioRxiv2021

Organ-specific metabolic pathways distinguish prediabetes, type 2 diabetes and normal tissues

Defects in pancreatic islets and the progression of multi-tissue insulin resistance in combination with environmental factors are the main causes of type 2 diabetes (T2D). Mass spectrometry-based proteomics of five key-metabolic tissues on a cohort of 42 multi-organ donors provided deep coverage of the proteomes of pancreatic islets, visceral adipose tissue (VAT), liver, skeletal muscle and serum. Enrichment analysis of gene ontology (GO) terms built a tissue-specific map of the chronological order of altered biological processes across healthy controls (CTRL), pre-diabetes (PD) and T2D subjects. This unique dataset allowed us to explore alterations of entire biological pathways and individual proteins in multiple tissues. We confirmed the significant decrease of the citric acid cycle and the respiratory electron transport in VAT and muscle of T2D and we provided a thorough visual representation of the complete set of downregulated proteins. Importantly, we found widespread novel alterations in relevant biological pathways including the increase in hemostasis in pancreatic islets of PD, the increase in the complement cascade in liver and pancreatic islets of PD and the elevation in cholesterol biosynthesis in liver of T2D. Overall, our findings suggest inflammatory, immune and vascular impairments in pancreatic islets as potentially causal factors of insufficient insulin production and increased glucagon levels in the early stages of T2D. In contrast alterations in lipid metabolism and mitochondrial function in the liver and VAT/muscle, respectively, became evident later in manifest T2D. This first multi-tissue proteomic map indicates the temporal order of tissue-specific metabolic dysregulation in T2D development.

cell biology↗

bioRxiv2021

High-Intensity Interval Training Remodels the Proteome and Acetylome of Human Skeletal Muscle

Exercise is an effective strategy in the prevention and treatment of metabolic diseases. Alterations in the skeletal muscle proteome, including post-translational modifications, regulate its metabolic adaptations to exercise. Here, we examined the effect of high-intensity interval training (HIIT) on the proteome and acetylome of human skeletal muscle, revealing the response of 3168 proteins and 1263 lysine acetyl-sites on 464 acetylated proteins. We identified global protein adaptations to exercise training involved in metabolism, excitation-contraction coupling, and myofibrillar calcium sensitivity. Furthermore, HIIT increased the acetylation of mitochondrial proteins, particularly those of complex V. We also highlight the regulation of exercise-responsive histone acetyl-sites. These data demonstrate the plasticity of the skeletal muscle proteome and acetylome, providing insight into the regulation of contractile, metabolic and transcriptional processes within skeletal muscle. Herein, we provide a substantial hypothesis-generating resource to stimulate further mechanistic research investigating how exercise improves metabolic health. Impact statementHostrup and colleagues identify global proteomic and acetylomic adaptations to high-intensity interval training, demonstrating adaptations to processes regulating metabolism and contraction.

physiology↗

bioRxiv2019

Mass-spectrometry based proteomics reveals mitochondrial supercomplexome plasticity

Mitochondrial respiratory complex subunits assemble in supercomplexes. Studies of supercomplexes have typically relied upon antibody-based protein quantification, often limited to the analysis of a single subunit per respiratory complex. To provide a deeper insight into mitochondrial and supercomplex plasticity, we combined Blue Native Polyacrylamide Gel Electrophoresis (BN-PAGE) and mass spectrometry to determine the supercomplexome of skeletal muscle from sedentary and exercise-trained mice. We quantified 422 mitochondrial proteins within ten supercomplex bands, in which we showed the debated presence of complex II and V. Upon exercise-induced mitochondrial biogenesis, non-stoichiometric changes in subunits and incorporation into supercomplexes was apparent. We uncovered the dynamics of supercomplex-related assembly proteins and mtDNA-encoded subunits within supercomplexes, as well as the complexes of ubiquinone biosynthesis enzymes and Lactb, a mitochondrial-localized protein implicated in obesity. Our approach can be applied to broad biological systems. In this instance, comprehensively analyzing respiratory supercomplexes illuminates previously undetectable complexity in mitochondrial plasticity. HighlightsO_LIComprehensive quantification of respiratory subunits within supercomplexes C_LIO_LIComplex II and V assemble within supercomplexes C_LIO_LIMitochondrial-encoded subunits display elevated upregulation upon exercise training C_LIO_LIExercise increases ubiquinone biosynthesis enzyme complexes C_LI

molecular biology↗

bioRxiv2018

Protein aggregation capture on microparticles enables multi-purpose proteomics sample preparation

Universal proteomics sample preparation is challenging due to the high heterogeneity of biological samples. Here we describe a novel mechanism that exploits the inherent instability of denatured proteins for non-specific immobilization on microparticles by protein aggregation capture. To demonstrate the general applicability of this mechanism, we analyzed phosphoproteomes, tissue proteomes, and interaction proteomes as well as dilute secretomes. The findings presents a practical, sensitive and cost-effective proteomics sample preparation method.

biochemistry↗

bioRxiv2018

Proteomics-based comparative mapping of the human brown and white adipocyte secretome reveals EPDR1 as a novel batokine

Secreted proteins from adipose tissue play a role in metabolic cross-talk and homeostasis. We performed high sensitivity mass spectrometry-based proteomics on the cell media of in vitro differentiated, non-immortalized brown adipocytes derived from supraclavicular adipose of adult humans and white adipocytes derived from subcutaneous adipose of adult humans. We identified 471 potentially secreted proteins covering interesting protein categories such as hormones, growth factors, growth factor binding proteins, cytokines, extracellular matrix proteins, and proteins of the complement system, which were differentially regulated in brown and white adipocytes. A total of 101 proteins were exclusively quantified in brown adipocytes, among these ependymin-related protein 1 (EPDR1). Ablation of EPDR1 impaired the induction of thermogenic transcripts in response to norepinephrine in brown adipocytes, while EPDR1-treated mice increased their energy consumption, suggesting a role in brown fat commitment and activation. Our work reveals substantial differences between the secretomes of brown and white human adipocytes and identifies novel candidate batokines.

physiology↗