bims-mimead Biomed News
on Adipose tissue and metabolic disease
Issue of 2025–03–30
twelve papers selected by
Rachel M. Handy, University of Guelph



  1. Mol Metab. 2025 Mar 24. pii: S2212-8778(25)00033-X. [Epub ahead of print] 102126
      Adipose tissue is a central player in energy balance and glucose homeostasis, expanding in the face of caloric overload in order to store energy safely. If caloric overload continues unabated, however, adipose tissue becomes dysfunctional, leading to systemic metabolic compromise in the form of insulin resistance and type 2 diabetes. Changes in adipose tissue during the development of metabolic disease are varied and complex, made all the more so by the heterogeneity of cell types within the tissue. Here we present detailed comparisons of atlases of murine WAT in the setting of diet-induced obesity, as well as after weight loss induced by either vertical sleeve gastrectomy (VSG) or treatment with the GLP-1 receptor agonist semaglutide. We focus on identifying populations of cells that return to a lean-like phenotype versus those that persist from the obese state, and examine pathways regulated in these cell types across conditions. These data provide a resource for the study of the cell type changes in WAT during weight loss, and paint a clearer picture of the differences between adipose tissue from lean animals that have never been obese, versus those that have.
    DOI:  https://doi.org/10.1016/j.molmet.2025.102126
  2. Cell Rep Med. 2025 Mar 22. pii: S2666-3791(25)00115-6. [Epub ahead of print] 102042
      Interleukin-6 (IL-6) knockout mice and humans treated with IL-6 receptor blockade gain adipose tissue mass. This study investigates whether basal IL-6 activity (resting IL-6 levels) influences fat storage during fasting and postprandial states. Using stable-isotope tracer techniques and IL-6 receptor blockade with tocilizumab, we examine fat kinetics in humans. Blocking basal IL-6 activity reduces fasting whole-body lipolysis, decreases hormone-sensitive lipase (HSL) phosphorylation and fatty acid release in adipose tissue, and impairs postprandial fatty acid uptake in the leg. These results suggest diminished fatty acid uptake and oxidation in skeletal muscle, along with enhanced fatty acid entrapment in adipose tissue, which may account for the increased adiposity in the absence of IL-6 activity. Additionally, IL-6 blockade increases the escape of meal-derived fatty acids into the bloodstream. Whether this affects fatty acid storage and lipotoxicity in other tissues warrants further investigation. This study was registered at ClinicalTrials.gov (NCT04687540).
    Keywords:  fasting; fatty acids; homeostasis; humans; interleukin-6; isotopes; lipolysis; nutrients; obesity; tocilizumab
    DOI:  https://doi.org/10.1016/j.xcrm.2025.102042
  3. Obesity (Silver Spring). 2025 Mar 23.
       OBJECTIVE: The obesity epidemic, driven by a complex interplay of environmental and biological factors, remains a significant global health challenge. Herein, we investigate the impact of food insecurity, characterized by unpredictable food access, on the regulation of body weight and body composition in mice.
    METHODS: Male and female C57BL/6J mice were subjected to a combination of intermittent fasting and calorie restriction to simulate food insecurity.
    RESULTS: Our new model demonstrates that food insecurity increases fat mass and decreases lean mass in both sexes on a standard chow diet. Additionally, high-fat diet-fed male mice exposed to the food insecurity paradigm show decreased lean mass despite being in positive energy balance. Transcriptomic analysis of white adipose tissue from food-insecure male mice revealed upregulation of metabolic pathways associated with fat mass expansion and downregulation of immune response-related transcripts.
    CONCLUSIONS: These findings underscore the role of food insecurity in driving metabolic adaptations that favor fat storage. Understanding this paradoxical link between food insecurity and adiposity is crucial for developing targeted interventions to address the disproportionate incidence of obesity in socioeconomically disadvantaged populations.
    DOI:  https://doi.org/10.1002/oby.24259
  4. Lipids Health Dis. 2025 Mar 27. 24(1): 118
       BACKGROUND: Visceral adipose tissue (VAT) is strongly associated with metabolic diseases. Both high-intensity interval training (HIT) and moderate-intensity training (MIT) reduce VAT effectively; however, HIT might mediate greater VAT loss in females. The estrogen receptor α (ERα) pathway may play a key role. The aim of the present study was to confirm the role of adipose/hypothalamic ERα in HIT/MIT-mediated VAT loss, as well as the associated hypothalamic electrophysiology and body catabolism changes in pre- and post-menopausal animal models.
    METHODS: Ovariectomy (OVX) or sham surgeries were conducted to establish pre/postmenopausal female rat models. After distance-matched long-term HIT and MIT interventions, ERα expression in hypothalamic/VAT, as well as food intake, spontaneous physical activity (SPA), VAT mass and morphology, local field potential (LFPs) in paraventricular nuclei (PVN) and excessive post-exercise oxygen consumption (EPOC), were observed. A target chemical block during the post-exercise recovery period was executed to further verify the role of the hypothalamic ERα pathway.
    RESULTS: HIT enhanced the expression of ERα in the hypothalamus rather than VAT in the pre-, but not the postmenopausal group, which was accompanied by elevated LFP power density in α and β bands, enhanced EPOC and larger VAT loss than MIT. Chemical blockade of ERα suppressed EPOC and VAT catabolism mediated by HIT.
    CONCLUSION: During the post-exercise recovery period, the hypothalamic ERα pathway involved in HIT induced EPOC elevation and VAT reduction in premenopausal female rats.
    Keywords:  ERα; Female; HIT; Hypothalamus; Visceral adipose tissue
    DOI:  https://doi.org/10.1186/s12944-025-02533-6
  5. JCI Insight. 2025 Mar 25. pii: e183706. [Epub ahead of print]
      Adult stem cells decline in number and function in old age and identifying factors that can delay or revert age-associated adult stem cell dysfunction are vital for maintaining healthy lifespan. Here we show that Vitamin A, a micronutrient that is derived from diet and metabolized into retinoic acid, acts as an antioxidant and transcriptional regulator in muscle stem cells. We first show that obstruction of dietary Vitamin A in young animals drives mitochondrial and cell cycle dysfunction in muscle stem cells that mimics old age. Next, we pharmacologically targeted retinoic acid signaling in myoblasts and aged muscle stem cells ex vivo and in vivo and observed reductions in oxidative damage, enhanced mitochondrial function, and improved maintenance of quiescence through fatty acid oxidation. We next detected the receptor for vitamin A derived retinol, stimulated by retinoic acid 6 or Stra6, was diminished with muscle stem cell activation and in old age. To understand the relevance of Stra6 loss, we knocked down Stra6 and observed an accumulation of mitochondrial reactive oxygen species, as well as changes in mitochondrial morphology and respiration. These results demonstrate that Vitamin A regulates mitochondria and metabolism in muscle stem cells and highlight a unique mechanism connecting stem cell function with vitamin intake.
    Keywords:  Adult stem cells; Aging; Muscle; Muscle biology; Stem cells
    DOI:  https://doi.org/10.1172/jci.insight.183706
  6. PLoS One. 2025 ;20(3): e0319163
      Obesity, a global public health concern, is influenced by various factors, including genetic predispositions. Although many obesity-associated genes have been identified through genome-wide association studies (GWAS), the molecular mechanisms linking these genes to adipose tissue function remain largely unexplored. This study integrates proteomic data on adipocyte fat accumulation with GWAS data on obesity to unravel the roles of the identified key candidate genes - G protein subunit beta 1 (GNB1) and scavenger receptor class B member 2 (SCARB2) - involved in fat accumulation. We utilized RNA interference to knock down GNB1 and SCARB2 in human subcutaneous adipocytes, followed by lipidome and proteome analyses using mass spectrometry. Knockdown of these genes resulted in a reduction in lipid droplet accumulation, indicating their role in adipocyte lipid storage. Digital PCR confirmed effective gene knockdown, with GNB1 and SCARB2 mRNA levels significantly reduced. In total, the lipidomic analysis identified 96 lipid species with significant alterations. GNB1 knockdown resulted in a decrease in cholesterol esters and an increase in phosphatidylcholines, phosphatidylinositols, and ceramides. SCARB2 knockdown also led to an increase in phosphatidylcholines, with a trend towards decreased triacylglycerols. Proteomic analysis revealed significant changes in proteins involved in lipid metabolism and adipocyte function, including PLPP1 and CDH13, which were upregulated following GNB1 knockdown, and HSPA8, which was downregulated. Conversely, SCARB2 knockdown resulted in the downregulation of PLPP1 and METTL7A, and the upregulation of PLIN2, HSPA8, NPC2, and SQSTM1. Our findings highlight the significant roles of GNB1 and SCARB2 in lipid metabolism and adipocyte function, providing insights that could inform therapeutic strategies targeting these regulatory genes in obesity.
    DOI:  https://doi.org/10.1371/journal.pone.0319163
  7. Cell Mol Gastroenterol Hepatol. 2025 Mar 21. pii: S2352-345X(25)00045-1. [Epub ahead of print] 101504
       BACKGROUND AND AIMS: Patients with obesity and mouse models of obesity exhibit abnormalities in intestinal epithelial cells, including enhanced stemness. Adipose tissue (AT) is the largest endocrine organ secreting cytokines, hormones, and extracellular vesicles (EVs). Here, we characterized EV protein cargo from obese and non-obese AT and demonstrate the role of obese adipose-derived EVs in enhancing colonic stemness.
    METHODS: EVs were isolated from visceral AT from mice fed high-fat diet to induce obesity or control matched-diet. EV cargo was characterized by unbiased proteomics. Mouse colonoids were treated with EVs and analyzed for fatty acid β-oxidation (FAO), expression of stem marker genes, stem function, and β-catenin expression and acetylation. Mice deficient in adipocyte-specific Tsg101 expression were generated to alter adipocyte EV protein cargo and colonic stemness was measured.
    RESULTS: EVs secreted from obese visceral AT (Ob EVs) were significantly enriched with acyl-CoA dehydrogenase long chain (ACADL), an initiator enzyme of FAO. Compared to non-obese EVs, colonoids treated with Ob EVs exhibited increased exogenous ACADL protein expression, FAO, growth, persistence of stem/progenitor function, and increased β-catenin protein expression and acetylation that was abolished by FAO inhibition. Mice deficient in adipocyte-specific Tsg101 expression exhibited Ob EVs with altered protein expression profiles and were protected from obesity-induced enhanced colonic stemness.
    CONCLUSIONS: The contents of Ob EVs are poised to fuel FAO and to promote obesity-induced stemness in the colon. Alteration of metabolism is a key mechanism of adipose-to-intestinal tissue communication elicited by EVs, thereby influencing basal colonic stem cell homeostasis during obesity.
    Keywords:  ACADL; Lgr5; colon; epithelial cells; metabolism; obesity; stem cells
    DOI:  https://doi.org/10.1016/j.jcmgh.2025.101504
  8. Eur J Clin Invest. 2025 Mar 26. e70033
       OBJECTIVE: Despite growing evidence, the mechanisms connecting adipose tissue (AT) function to type 2 diabetes (T2DM) remain incompletely understood. A detailed analysis of AT transcriptomes could offer valuable insights into this relationship. Here, we examined gene expression patterns in bulk subcutaneous AT, focusing on biological pathways and cellular composition associated with glycated haemoglobin (HbA1c) levels.
    METHODS: A transcriptomic dataset was obtained from subcutaneous AT samples of 901 adults collected during elective surgical procedures. We characterized cellular composition within subcutaneous AT in association with blood HbA1c levels by performing bulk adipose transcriptomes cell deconvolution analysis. We also conducted differential gene expression and overrepresentation analyses. We validated our cross-sectional study using two independent validation cohorts, performing further downstream analyses.
    RESULTS: Subcutaneous AT from subjects with increased HbA1c had lower adipocytes, smooth muscle, pericytes and other endothelial cell numbers. Pathways associated with HbA1c levels included cellular senescence and telomere-related pathways and extracellular matrix organisation. We identified the expression of RHO GTPases associated with HbA1c not previously linked to glucose homeostasis, with a possible sexual dimorphism shaped by the obesity state. The findings were confirmed in both longitudinal cohorts. At the gene level, HLA-DR, CCL13, and S100A4 mRNA levels were strongly correlated with HbA1c levels.
    CONCLUSIONS: This study underscores the utility of AT transcriptome analysis in unravelling T2DM complexities. Our findings enhance knowledge of glucose homeostasis' molecular and cellular underpinnings, paving the way for potential therapeutic targets to mitigate the impact of AT dysfunction in metabolic diseases.
    Keywords:  Rho GTPases; glycated haemoglobin; immune system; subcutaneous adipose tissue; type 2 diabetes mellitus
    DOI:  https://doi.org/10.1111/eci.70033
  9. Mol Metab. 2025 Mar 20. pii: S2212-8778(25)00035-3. [Epub ahead of print] 102128
       BACKGROUND: Chronic high-fat diet (HFD) feeding triggers hypothalamic inflammation and systemic metabolic dysfunction associated with endoplasmic reticulum (ER) stress. Glial cells, specifically microglia and astrocytes, are central mediators of hypothalamic inflammation. However, the role of Inositol-Requiring Enzyme 1α (IRE1α), a primary ER stress sensor, in glial cells and its contributions to metabolic dysfunction remains elusive.
    OBJECTIVES: To investigate the role of IRE1α in microglia in mediating HFD-induced metabolic dysfunction.
    METHODS: Using novel conditional knockout mouse models (CX3CR1GFPΔIRE1 and TMEM119ERΔIRE1), we deleted IRE1α in immune cells or exclusively in microglia and studied its impact on metabolic health and hypothalamic transcriptional changes in mice fed with HFD for 16 weeks.
    RESULTS: Deleting IRE1α in microglia significantly reduced LPS-induced pro-inflammatory cytokine gene expression in vitro. IRE1α deletion in microglia protected male mice from HFD-induced obesity, glucose intolerance, and hypothalamic inflammation, with no metabolic benefits observed in female mice. RNA-sequencing revealed significant transcriptional reprogramming of the hypothalamus, including upregulation of genes related to mitochondrial fatty acid oxidation, metabolic adaptability, and anti-inflammatory responses.
    CONCLUSIONS: Our findings reveal that IRE1α-mediated ER stress response in microglia significantly contributes to hypothalamic inflammation and systemic metabolic dysfunction in response to HFD, particularly in males, demonstrating an important role of microglial ER stress response in diet-induced obesity and metabolic diseases.
    Keywords:  ER stress; Hypothalamic inflammation; Hypothalamus; Microglia; Neuroinflammation; UPR
    DOI:  https://doi.org/10.1016/j.molmet.2025.102128
  10. GHM Open. 2023 Aug 31. 3(1): 7-19
      Adipose tissue (AT) acts as a highly active endocrine organ, which secretes a wide range of adipokine hormones. In the past few years, several adipokines (leptin, adiponectin, resistin etc.) have been discovered showing metabolic consequences in relation to insulin resistance (IR), obesity and diabetes. These adipokines are considered to be an important component playing an important role in the regulation of energy metabolism. They have been shown to be involved in the pathogenesis of metabolic syndrome (MetS) and cardiac diseases. The current article provides a holistic summary of recent knowledge on adipokines and emphasizes their importance in association with IR, obesity, diabetes and MetS. Adipokines such as leptin, adiponectin, resistin and tumor necrosis factor-alpha (TNF-α) have been involved in the regulation of an array of metabolic functions and disease associated with it, e.g. appetite and energy balance of the body, suppression of atherosclerosis and liver fibrosis, obesity with type 2 diabetes (T2D) and IR. An important adipokine, Interleukin-6 (IL-6), also correlates positively with human obesity and IR and also the elevated level of IL-6 predicts development of T2D. All of these hormones have important correlation with energy homeostasis, glucose and lipid metabolism, cardiovascular function and immunity. All the possible connections have extended the biological emphasis of AT secreted adipokines as an investigator in the development of MetS, and are now no longer considered as only an energy storage site.
    Keywords:  adipose tissue; appetite; glucose; homeostasis; lipid
    DOI:  https://doi.org/10.35772/ghmo.2023.01004
  11. Adv Exp Med Biol. 2025 Mar 26.
      Mitochondria play a critical role in cellular communication, cell proliferation, and apoptosis, which make them essential to maintaining cellular health. Recently, mitochondrial transplantation has emerged as a promising therapeutic approach to treat conditions such as ischemia, neurodegenerative diseases, and cardiovascular disorders by restoring mitochondrial function in damaged cells. Despite its potential, understanding mitochondrial behavior in vivo remains challenging; however, organoid models, which are three-dimensional structures derived from stem cells that mimic human tissues, offer a solution to study mitochondrial function and transplantation strategies under controlled conditions. These models are particularly necessary in studies, as they can replicate disease conditions and consequently enable researchers to investigate mitochondrial dynamics and therapeutic integration. Developing organoid systems optimized for mitochondrial transplantation requires exploring factors that influence mitochondrial uptake, refining transplantation strategies, and understanding their role in cellular regeneration in order to advance in the field of mitochondrial research.
    Keywords:  3D cell culture models; Delivery methods in organoids; Mitochondria; Mitochondrial transplantation; Organoids
    DOI:  https://doi.org/10.1007/5584_2025_857
  12. Function (Oxf). 2025 Mar 25. pii: zqaf017. [Epub ahead of print]
      Apolipoprotein E4 (APOE4) is the greatest genetic risk factor for Alzheimer's (AD) and is linked to whole-body metabolic dysfunction. However, it's unclear how APOE4 interacts with modifiable factors like diet to impact tissues central to regulating whole-body metabolism. We examined APOE4- and Western diet-driven effects in skeletal muscle using APOE3 (control) and APOE4 targeted replacement mice on a C57BL/6NTac background fed a high-fat diet (HFD, 45% kcal fat) or low-fat diet (LFD, 10% kcal fat) for four months (n=7-8 per genotype/diet/sex combination). We assessed body composition and whole-body outcomes linked to skeletal muscle function including respiratory exchange ratio (RER) and resting energy expenditure (REE). In skeletal muscle, we evaluated the proteome and mitochondrial respiration. In males only, APOE4 drove greater gains in fat mass and lower gains in lean mass on both diets. APOE4 did not affect daily RER but was associated with elevated REE in males and lower REE in HFD females after covarying for body composition. Skeletal muscle proteomics showed APOE4 exerts several diet- and sex-specific effects on mitochondrial pathways, including elevations in branched-chain amino catabolism in HFD males and reductions in oxidative phosphorylation in LFD females. This did not translate to differences in skeletal muscle mitochondrial respiration, suggesting that compensatory mechanisms may sustain mitochondrial function at this age. Our work indicates that genetic risk may mediate early life effects on skeletal muscle mitochondria and energy expenditure that are partially dependent on diet. This has important implications for mitigating AD risk in APOE4 carriers.
    Keywords:   APOE4 ; Alzheimer's; mice; mitochondria; proteomics; skeletal muscle; whole-body metabolism
    DOI:  https://doi.org/10.1093/function/zqaf017